Hi Mark, to me that isn't a problem, but instead it works as intended (overriding 'saved' curve presets).
The last thing I'd want, is to load a project only to find that I had 'global curves' set to 'on' (esp. like you say, with a radically different curve.. it's likely to be difficult to re-edit it to match).
So, the cheapest, no cost way to avoid that failure, is to say NO to global velocity curves in projects!
If it's desired to keep fixed (unchanged) velocity curves within DAW projects in any circumstances, I'd really just avoid engaging the global velocity curve.. it's designed for users to override the current 'set' preset.. so in a way, it's just throwing dice to use it in projects.
Sincerely, hope this helps anyone wondering about it. It's definitely not a bug or a weird fault.
Here's an example of what you can do to 'future proof' or save your DAW projects from a certain amount of what I call 'project rot'
First thing, like above - don't rely on anything 'unsaved' whether it's Pianoteq velocity curve 'alterations' on the fly or using a global curve (those can change - you may edit a preset later, and then load a project and it differs enough to, like mentioned, sound too differently to the original nature of the project).
Examples of 'saving' things..
Firstly this may not be obvious perhaps, but we can save presets for individual things like "velocity curves".. things like "mic settings", even the entire FX section (so you can re-load some things including reverb and EQ, compression and chorus FX or whatever you may wish to re-load to use with other pianos you loaded).
Other saves to consider.. if you changed your velocity curve (and expect to use it often - but do not wish it to be your global 'always on' curve), you can save it as a preset to re-use at any time. Name it in a way which resonates for you "MyCurveForChopinOnPianoX-Nov2024".. or "My Velocity Curve for Project Y - Nov 2024 - version E" - or "mrY next nEw CRuirve yDingruz" - but don't leave it there... if you load into a DAW project with another preset.. but wish to use your new curve.. sure, within Pianoteq load that preset in... but don't just save the whole project.. tie the curve to the preset.. in Pianoteq "Save as" and give the 'full preset' a new name.. so you know for sure (TM) that it's done, finished, ready and waiting for next time
Other no-cost ways to avoid DAW project rot, include "bounce your instrument tracks to audio tracks".. Reaper and many DAWs have a 'Freeze' feature (different to Pianoteq's Freeze function).. the DAW Freeze generally bounces your instrument to a new audio track and handily may mute your instrument track.
There are different ways to do those kinds of things. For one example, I might use "Song/Mix down" as an operation on an instrument track, IF I wish the new resulting audio track to include any DAW FX as well.
Just check your DAW settings and the features it may offer, for turning instrument tracks to audio. In my DAW of choice (Studio One) I tend to mainly use "bounce to a new audio track" which does not include any FX I might have set.. or like mentioned 'Song/Mix down to new audio track' and that will include all FX in the 'bounce' ... and if doing that, it's up to me, and a user's prerogative to make use of the checkbox "import audio as new track" in the dialog for that operation.
I stop here because it's easy to get lost in ways to avoid project rot.. but for sure - I would avoid something like global curves in projects.. obviously because, like you found out.. you can edit/change it and it won't save. In fact, because it doesn't save to a perma state is kind of its super power. Hoping that all makes sense if interested in this kind of thing.
Pianoteq Studio Bundle (Pro plus all instruments) - Kawai MP11 digital piano - Yamaha HS8 monitors