[Dovecot] Questions regarding dbox migration

[Mikkel]

It has been my wish to move to dbox for a long time hoping to reduce the 
number of writes which is really killing us.

Now I wonder what may be the best way of doing so. I'm considering some 
sort of intermediate migration where the existing Maildir users are 
changed to single-dbox and then later upgraded to 2.0 and changed to 
multi-dbox when it becomes stable.
But is this a reasonable task to perform on a production system or at 
all? The alternative is to wait for 2.0 to become completely stable and 
then go all the way at once.
I would however much prefer to take it one step at a time and I think it 
would be safer to start out with single-dbox as it appears less complex.

Now the big question is whether multi-dbox and single-dbox are 
compatible formats.
If a Maildir->dbox migration is made on a system running dovecot v. 1.1, 
would it then be trivial later changing to multi-dbox after upgrading to 
2.0 or is a completely new migration then needed?
Would this scenario be much different if the system is upgraded to 
version 1.2 before the change to single-dbox?

Kind regards, Mikkel