To be honest reading this thread has made me have little hope in Avid... Seems a few people in here might be working for them too...
Taking a read at
https://avid.secure.force.com/pkb/ar...d/Mbox-Drivers
it seems that they don't really care to offer much help at all...
Its 2021 and would take no time at all for them to give us a 64bit update...
It's a shame none of us here are really programmers or you could actually write a kext to support this...
I am saying hang in there guys and there might be something that pops up in the near future...
One thing to also suggest from that
https://www.usb-audio.com/ link that was posted here as a work around for the older USB Mbox's
If you look into their page they state the following "macOS Big Sur 11 no longer loads kernel extensions, it's not possible for us to provide an update."
That means there is no current way and possibly no way in the future for them to operate the workarounds that they do...
It really seems like these problems we face are a combination of Apples plans and Avids plans for the future. It's just a shame that Avid can't warrant their customers enough to provide us with a fix to what really is a very simple issue. Windows can provide workability for 64bit and 32bit apps so there is no reason why Apple cannot... I might have to say goodbye to Apple now and also goodbye to Avid just like many others here seem to say!