The OpenPOWER RISC systems fit nicely in the middle-tier niche.
POWER is also known for being highly SMT, which could lead to them being even more prone to the issues that plagued Intel's implementation of hyperthreading. A single POWER9 core has 4 to 8 threads.
Or maybe POWER9 is completely secure.
My main point was that Epyc has already proven to be much more resistant to these attacks than Intel’s architecture, and it wouldn’t require dealing with porting your applications to run on a niche ISA, with very limited options to buy server hardware, and very few (if any) options to rent cloud instances on POWER9.
Which SMT issues are you referring to here on Intels?