Some comments:

1. I think the "nowear" cheatcode should not always be used. When doing heavy work involving the persistent store, like package upgrading, I think it may be better to skip the ramdisk layer. The ramdisk layer is for "everyday", not "administrative" use.

2. If we often find ourselves doing lots of heavy work with the persistent store - why are we doing it there? Much better to mount extra partitions and use them directly. Myself, I now find that I need about 4GB persistent store for comfort, but not more. Rather remaster, if programs fill it up, or move data out.

3. With modest modifications, how much does it matter if the ramdisk crashes without having been written to persistent store now and then? And with laptops, power outage is normally not a reason for crash.

4. I wonder what is so terribly impractical with an aubrsync-based scheme, where the ramdisk is normally copied at shutdown, but there is also an option to close X, unmount&update persistent store, and remount/restart X. That is safe, and I wonder where the pressing performance/use issues lie that motivate giving up on safety?