Well, I thought that channel trim was a digital process, but that doesn't mean that it actually is the case - after all, the main volume control is done in the analog domain. You might ask Outlaw, either by phone or online ...

As for the list of changes, I believe that the quote below (taken from the announcement for the new firmware) is the summary of changes for this firmware update.
The support page still lists the changes implemented in 3.10/3.11, so it would be worthwhile to update it - possibly with the specific changes spelled out.