SME is just the AMX coprocessor that’s been in Apple chips since 2019. SME made it easier to target the AMX. But it’s been in use and available to developers since 2019.
AMX has been present in every M series chip and the A series chips starting with the A13. If you are comparing M series chip scores in Geekbench 6 they are all using it, not just the latest ones.
Any app using Apple's Accelerate framework will take advantage of it.