The normal way for an organization to publish a serious report is to create a PDF with the logo of the organization. Instead leaving it at the level of forum posts / Google doc drafts seems to me a way to make it appear less as a serious report.
It's hard to skim
I don't think these are necessarily mutually exclusive, but we might have to work with alternative formats. But that's a good idea anyway. Here's an example for Bostrom's Astronomical Waste.
It's hard to distinguish sincere claims from hyperbolic ones
This is not really a problem if they're being honest around it. I'm recommending being serious about your silliness, not letting go of your seriousness.
All of your favorite writers probably use it already to some degree. Scott Alexander for instance has explicitly talked about using "microhumor", which can be a combination of hyperbole and hedging (or hypobole? Maybe that's what this skill should be called.)
This can be more challenging for non-native speakers, in both the cultural and language sense. But that's also a tradeoff with, for example, jargon usage.
People might get away with a response of "I was clearly joking" when you provide critique
Yes, they might. There is no language in which it is impossible to write bad programs. If there is such a confusion, they can be transparent about the point of the tone.
It's hard to reference
There are two reasons for this. One is the "can't skim" objection addressed earlier. The other is optics. I don't have much to say if you're balancing optics. Damn Moloch.
I find this style annoying/insulting
Check if it might be worth informing this aesthetic, given the benefits. Also, as noted earlier, a lot of your favorite writers might be using it already, so well that you don't notice it. Which requires practice.
If you're reasonably practiced at it and still think it's net negative, I'm interested in hearing your objection!
It's hard to structure
I think this is true, but not incredibly so. The costs diminish. It might even come easier to you.
It looks weird/silly
I'd say in a good way, when done right. That's a feature.
Also, formalese is the weird and unnaturally stiff one.
I'd rather just state my credences seriously instead of these acrobatics
Nate has a post called Confidence All The Way Up. It's a pretty great post, about covering each layer of uncertainty with meta-certainty, all the way up. But it doesn't have many pointers for communicating a summary of many layers succinctly. A facetious tone is a stickier and concise way of communicating your imprecision than writing out several layers of uncertainty by hand. It's (arguably) less distracting. Importantly, it's less painful, and so you're more likely to actually do it. Additionally, it's pretty well-known that precision of content alone does not translate to precision in the reader's world-model. So taking some responsibility for the whole thing makes sense.
In sum: solemnly stating your (meta)uncertainty might give people the sense that you're pretty certain about your (meta)uncertainty. If that is indeed what you want to communicate, great. Either way, learning how to modulate tone can add to your repertoire.
I'm not funny
You don't have to be! But you can work on adding choice in the style you use.
Here's a quote from Eliezer to round it off, from Against Maturity (emphasis mine):
Robin is willing to tolerate formality in journals, viewing it as possibly even a useful path to filtering out certain kinds of noise; to me formality seems like a strong net danger to rationality that filters nothing, just making it more difficult to read.
Robin seems relatively more annoyed by the errors in the style of youth, where I seem relatively more annoyed by errors in the style of maturity.
And so I take a certain dark delight in quoting anime fanfiction at people who expect me to behave like a wise sage of rationality. Why should I pretend to be mature when practically every star in the night sky is older than I am?
TL;DR Tone can function like (im)precision. So work on the ability to choose its variation instead of some arbitrary thing choosing it for you.
The ability to write in a facetious tone is a wonderful addition to one's writing toolset, equivalent to the ability to use fewer significant digits. This is a separate feature from the features of "fun to read" and "irreverent". People routinely mistake formalese for completeness/rigor, and the ability to counter that incorrect inference in them is very useful.
At some point in Eliezer's post against bioanchors, he roleplays Open Philanthropy as saying:
OpenPhil: We have commissioned a Very Serious report on a biologically inspired estimate of how much computation will be required to achieve Artificial General Intelligence, for purposes of forecasting an AGI timeline. (Summary of report.) (Full draft of report.) Our leadership takes this report Very Seriously.
Here's Holden's reply to that specific bit:
It's true that Open Philanthropy's public communication tends toward a cautious, serious tone (and I think there are good reasons for this); but beyond that, I don't think we do much to convey the sort of attitude implied above. The report's publication announcement was on LessWrong as a draft report for comment, and the report is still in the form of several Google docs. We never did any sort of push to have it treated as a fancy report.
The tendency towards mistaken impressions from formalese is common knowledge (at least, after this post). So "We never did any sort of push to have it treated as fancy" becomes about as defensible as "We never pushed for the last digits in the estimate 'There are 45,321 hairs on my head' to be treated as exact", which... is admittedly kinda unfair to Holden. Mainly because incorporating a writing style is a much harder execution than replacing some digits with zeros.
Eliezer is facetiously pointing out the non-facetiousness in Open Phil's report (and therefore doing some of the facetiousness-work for them), and Holden solemnly points out the hedged-by-default status of it, which... is admittedly kinda fair for Holden to do. But I'm glad this whole exchange (enabled by facetiousness) happened, because it causes the hedged-by-default-ness to be emphasized.
(He did say they have good reasons for a serious tone. And I do believe there are good reasons for it, such as having to get through to people who wouldn't take them seriously otherwise, or some other silly Keynesian beauty contest. But my guess is that those constraints would apply less on what people post to this forum, which is evidence that their default tone is more about labor and skill than a carefully-arrived-at choice.)
Some other reasonable objections are addressed in a comment I've made below, but overall: There may be good objections to using it all the time, but not to learning to use the skill, which would involve learning when to not use it. As an example, I considered making the objections comment below more conversational, but I decided against it to allow order-independence.