For another perspective, whenever I collab, I just ask upfront which of us would host things in a primary DAW (if in fact we are comfortable in different DAWs), depending on who feels better about mixing and project organization. That person handles the MIDI and plugin work, and "commits" to less when it comes to set ideas. Also, I find that it would make it easier, at least for one of us, to have an idea of what the big picture of the project is, as it isn't scattered between two DAWs.
In terms of what happens in between, typically I openly recommend that we often send rendered WIPs each other's way for feedback before finally sending the newest version of the tracks (rather than sending it because of a lack of inspiration or something). That way, we minimize fudge factors in mixing, or reworking a performance, etc. because someone found a error in the middle of working on the track that would be frustrating to fix. It also keeps the shared vision as clear as possible so that we can both see what we both want.
On the other hand, if we have two people in different DAWs writing something and sending WAVs to each other, eventually it could get confusing whose ideas are newer (say, if one of them decide to work ahead because they felt inspired), so that's why I prefer to have one person doing things on a primary DAW between the collaborators.
Furthermore, if it is done that first way (well-defined roles), ideas shouldn't feel as "set", even if you're bouncing WAVs to send to the other person; because one person can write in regular MIDI, and the other person is bouncing WAVs, that other person can tell pretty easily how new their ideas are (although admittedly they might feel they have less control), and can update what they have at any time as long as the primary mixer doesn't mind some slight adjustments based on the updates.
You do what works for you, but that's how I tend to do it.
One thing that helps me, is the idea that TV composer Ron Jones talks about: Limiting yourself to "the main thing" and "the other thing" with the "other thing" being optional.
If you just limit yourself to focusing on something like writing the melodies for the entire piece before doing ANYTHING else, all that's left is to harmonize it, add percussion, etc.
It's why a lot of composers still start from just a piano sketch; no distractions or VSTs or anything like that to play around with.