morning walks, as close as possible to waking, fixed decades of sleep problems when all the other heavy duty interventions didn't.

The only reliable technique is exercise. Cardio at a pretty decent effort level -- got to really work up a sweat. If this is also done outside in the sun it's almost perfectly reliable. If indoors it's still pretty good. Maybe 70%.

Of course the problem is doing exercise is very likely one of the things I put off while meandering in the morning. But if I am able to force myself to do it, it usually does the trick.

Like Jaques, I also use focusmate to get up and running in the morning. I try to use the 10min between sessions to get ready. This timebox is helpful to me because I would otherwise drag it out. During these sessions, I find it beneficial to do the same things every morning. This way, I can go on autopilot until I am fully awake and don't have to will myself into doing stuff. 

When I notice this happens to me (sometimes when working alone from home), I set up a https://www.focusmate.com session. There’s some EAs on there too so it’s nice to see EAs once in a while. And I make sure to be specific about what I’ll work on during that session.

This doesn’t always work. Sometimes it takes a session or two to get into the flow of things. I usually only have sessions in the morning so it forces me to get up and get to work.

Not a direct answer, but this post has a ton of useful advice that I think would be applicable here: https://www.neelnanda.io/blog/mini-blog-post-19-on-systems-living-a-life-of-zero-willpower

Use alarms and don't ignore them, ever. Set the alarms to go off at the time when you want to start setting up for the next part of your day; e.g. getting ready for bed instead of lights-out time, setting up your workspace for the day instead of time to be fully productive, checking if you're hungry instead of lunchtime, &c. You can set as many labeled alarms as you like on your phone and many watches, and you can schedule them to repeat regularly. If you don't want to disturb people around you, set the alarm to vibrate and keep the device on your person. (A smart watch is exceptionally useful for this.)

If you need additional alarms to remind you to actually get started, set those too. I prefer to use just one alarm and let setup naturally flow into the intended activity, but do what you have to do to keep your day moving the way you want it to. Remember: never ignore your alarm. If you didn't want to do the thing, you shouldn't set the alarm in the first place! If you can't actually start "getting ready for bed" (or whatever) when the alarm goes off, acknowledge the alarm and begin moving toward that goal. The setup phase can start with whatever you're doing right now and ends when you're ready to do the next thing, but it's important to get that process moving!

Revisit your alarms as often as you need to to make sure you're cueing the right habits/systems. This will be more frequently at first, but as you settle in to the routine you want you can review less often. And don't be afraid to make changes if life takes an unexpected turn. If you think you might need an alarm later, turn it off instead of deleting it. That way you can just turn it back on again or reconsider deletion when you're more sure.

Keep alarms only for your normal schedule. For events that occur irregularly, infrequently, or just once (e.g. next month's game day, maintenance schedules, dentist appointments) schedule calendar reminders with appropriate lead times instead of setting alarms. This kind of reminder will vanish from your active systems automatically after it has fired, and you won't clutter up your alarm cluster with dead items.

If a consistent bedtime is a problem for you, try working from the other end. Getting up at the same time every day means that if you didn't get enough sleep you will be more tired in the evening and it will be easier to go to bed when you want. You can use this to explore how much sleep is optimal for your body and establish a bedtime you will want to keep.