Thanks for your response!
If in fact this goes down in the prioritizing process, it would really be great if you could, in the interim, provide some generic hook inside the md-then-mount process of the unRAID array start (and stop), so that a user can insert their own DM layer and probably mounting before unRAID does the standard share / user share setup.
(e.g.: Do the unRAID md - then call a script, which by default just copies its input to output, passing it the md block device (/dev/md*) - then mount the block device the script returns unless already mounted - something to that effect. Similarly for array stop).
This should be fairly straightforwrd to implement, and will enable the addition of an encryption layer, and perhaps other DM type ideas as well, by the user. No GUI support for now; no problem.
Thoughts?