It should be noted that “TCC” is a unique feature / restriction relevant only to Windows. It’s sole feature is to allow peering in the Windows environment where that is otherwise not available because of Windows OS restrictions. GeForce cards have always been restricted in terms of peering in Windows.
In Linux however, any version of Linux, TCC is irrelevant. What is relevant is hardware peer-to-peer capability enabling UVA (unified virtual addressing). Up until the 2000 series, All 900 series and 1000 series GeForce cards could peer (share memory) over pcie in Linux - which is really what this is all about.
Beginning in the 2000 series of GeForce cards, peer-to-peer cannot be achieved over pcie. You could connect up to 2 cards over NVLink that had that interface (2070+). That restriction applies both to Windows, Linux, or any other OS environment, as well.
If you’re doing serious multi-gpu compute - you aren’t likely to be using Windows as your platform. Thus TCC is kind of a moot point. Peer-to-peer in Linux, however, is not.