Regarding the "expensive overhead of boxed types", do we just need more work at the hardware ISA level (with pointer tagging or NaN-boxing) and we need the hard

Regarding the "expensive overhead of boxed types", do we just need more work at the hardware ISA level (with pointer tagging or NaN-boxing) and we need the hardware to be aware of those bits and handle them safely/properly via some minor extensions to RISC-V or Intel/AMD/Apple ISAs? Or do we have to have completely new forms of hardware datatypes?