[Darryl Ramm]

This still seems confused.

If you want to use an Omni, you need a HD or Ultimate software licenses, it will not work with Pro Tools standard, and after 12.6 you *also* need a DigiLink license (Which you get when you upgrade to Ultimate/HD Bundle).

Too much stuff here seems “I heard of problems” without you providing details. I am not aware of a DigiLink interface issue specific to the HD Thunderbolt box, if there is I expect folks would be screaming about it here... given that is how DigiLink is used with many Trashcans. And plugins? They may well have issues, or may not. Have you searched here or elsewhere to see if they work at all? Why don’t you ask here if anybody has the exact ones you are looking at running on your old OS?... or if you don’t need them then just don’t. You are looking at a lot of possible disruptive pain here.

I am also not sure that avoiding upgrading to Adobe Creative Cloud for $53/month is a good factor here. Upgrading to a Creative Cloud gets you the latest Adobe products... which I would expect to help you if you are working professionally with those tools (I used to work for Adobe on InDesign and related markets), ...and it’s a tax deduction for you. All vs. buying a Trashcan with all its challenges. And now start factoring in another ~$1k plus ~$600 in subsequent years for Pro Tools Ultimate... or needing to buy a new non-DigiLink interface. I am not sure avoiding $53/month for Creative Cloud really should be driving this decision without clearly understanding all the other costs.