Hi Alex, still investigating, sorry - we'll see what we can come up with. Two thoughts, can you send a simplified version of the scene for testing just in case we can't duplicate?
Another idea as a temporary workaround, depending on how much you like MaxScript, the useLegacyTiltShift parameter should still be accessible via maxscript to force the Legacy mode on. Of course this is just if you have one scene affected, no good if this is affected lots of scenes as you can't keep doing maxscript changes - but just in case it helps.
We'll let you know as soon as we have anything on this end, apologies for the inconvenience.