The feature is only on SPARC, not x86. Oracle killed in-house SPARC development in 2017, and they abandoned OpenSPARC after they acquired Sun, so it's effectively a dead architecture. The software won't work without the hardware to run it on.
Finally, it is up to Intel and AMD to come up with hardware memory tagging, so far they have messed up all attempts, with MPX being the last short lived one.
FAANG won’t send auditors to check whether your are in compliance with what license you paid for. Per core/socket licensing is one of the reasons POWER can do SMT/8.
