I know that in psychology almost nothing replicates, but it seems likely to me that most attempts at suppressing emotions lead to either their occassional outbursts, or mere denial. An archetypal example would be a person screaming with red face about how they are not angry -- that seems obviously harmful, even more so for a wannabe rationalist. On the other hand, if you redirect your anger into e.g. exercising, you can improve your health.

If people could reliably turn off their tribalism by pressing a button... I guess I would still have some doubts about turning off something that has an obvious evolutionary purpose... but I would be okay with other people doing potentially harmful experiments on themselves. But seems to me that when people e.g. avoid expressing membership in the rationalist tribe (sometimes proclaiming that they want to keep their identity small), what usually happens is that they already identify as members of some other tribe, and understand that double membership would create a few conflicts. It would be more honest to admit that, though.

But if you know that your brain is designed to create strong feelings about this or that tribe, and that those feelings can e.g. motivate you to overcome akrasia and do stuff that is approved by given tribe, you might harness that power by choosing a tribe whose goals appeal to you. Please understand that I am not saying that you should maximize the feelings of tribalism, or anything like that. Instead, simply accept that they exist, and choose a useful channel for them to flow in, as opposed to letting them find their own channels.