polanoid

...and I just tried this in 10.3.0, which seemingly is the oldest Logic Pro version that I can even start on Sonoma: Same as in 10.4.4. So if this was ever different for you, your version must have been at least as old as 10.2.4, i.e. 8 years. I would assume that even that version behaved like 10.4.4, but of course I can't prove it.

BTW 10.8.1 even behaves a bit better, if you will, than 10.4.4 in this regard, as it uses a timeout (I guess 10 seconds) after which a change of the same parameter does create another undo step. So if you change a region's gain, wait 11 seconds, then change the gain once more, you will have two undo steps. This does not happen in 10.4.4: You can wait as long as you like, repeated changes of the same parameter will always only result in one single undo step. I just verifed that in my 10.4.4 backup version.

person above‘s nick is polanoid. I still have 10.4.4 backed up on my computer, and the behavior is 100% identical to that of 10.8.1, no matter what you claim.

FWIW the same happens in 10.4.4 (which, according to your sig which might not yet be up to date, was the version you updated from?), I just checked. The behaviour makes sense IMO to keep the undo history from overflowing (i.e. old undo steps getting unnecessarily deleted) when tweaking a parameter multiple times.

Regions that are located before the first tempo change you delete should not move, so if that happens to you, maybe you could post a screenshot video of that?

That seems to have been a bug (I can reproduce it in 10.7.1), but it has been fixed in the meantime, no such issue in 10.8.1 EDIT It already seems to be fixed in 10.7.2, so you could easily update

OK in Logic speak, a Multi Instrument is an Environment object managing 16 external MIDI channels, so disregard what I wrote and thanks for the explanation. You're talking about Multi Out Aux channel strips (I guess?) which can of course not be negative-delayed individually as they only transport Audio signals. What if you set a "large enough" negative delay on the Instrument track and insert a Sample Delay plug-in in each multi-out aux, set its "Unit" to "ms" and add a positive delay to adjust the individual aux delay (which would then be the (negative) instrument delay plus the (positive) aux delay)?

Maybe an additional screenshot of your sidechained compressor's settings could be helpful too?

I just tried that, works just fine here. I'm not sure what you mean by that

If you can reproduce any of that, don't hesitate to post here

This was actually quite easy to track down... just input some signal, check which level meters go up, and look which input feeds the corresponding channel strip

So, unless Logic changed the Input of Aux 34 itself due to some issue (did it?), this was not Logic's fault.

Aux 34 (Ld Guitar Delay) routes Input 1-2 directly to Bus 30 which transports it to Aux 32 which in turn routes it to Bus 5, then to Bus 3 via Aux 8, then to Stereo Out via Aux 6.

So which Input are you getting the signal from? Seems your hardware has quite a lot of those

If possible, share the project so others can have a look at it