You are producing multiple different pieces of music in one project. They have different time signatures, different tempi, and the time signatures, tempi and absolute start times against the absolute timeline of the project can change. When making a change in tempo or signature there is a knock-on impact to everything further down the project which can mess everything up.
Incomplete and unsatisfactory workaround:
change musical tracks to linear and make the changes. This is unsatisfactory as anything further down the line is now not to an appropriate musical grid, and a nightmare to edit as you are working just with absolute time values.
There are a number of really complicated and really difficult solutions to develop but I wonder whether this simpler(?) possible solution might be easier to achieve and just as effective…
Multiple Grid Overlays.
So there’s already the main time format which can be set to timecode, time, musical etc., and this doesn’t have to change. Take this as the underlying absolute time format.
On top of this you place bounded time segments which overlay an independently configurable grid - much like a tracing paper overlay. So the underlying time format does not change, but you have multiple grids with absolute start times and bounded duration.
(A very basic type of overlay is done with the primary and secondary time displays already, but this is for the whole project.)
Maybe cycle markers could be extended for this purpose - for bounding each grid overlay. MIDI and audio regions could be given a property which binds them to a cycle marker. If you open a region up, the grid for display and quantize etc could now have “User Overlay” as an option. So you could move the cycle marker around the project, it would start at an absolute time on the project, but everything bound to that cycle marker would move with it and could stay on the User Overlay grid so that when you open a region it still makes musical sense and when you make changes elsewhere in the project it doesn’t have to impact everything later down the timeline.
A way for handling tempo and signature changes would need to be found. Maybe these could also be as blocks and bound to a cycle marker too(?).
I’d love to help design and test this with you if you thought it had legs. It would revolutionize the messy way I have to work with multiple different projects for one production to avoid the mess created when trying to work in a single project.