This is a very dangerous way of thinking. You cannot tell at the time of discovery if specific research will be useful or not down the line. You need to advance the research in all directions, even if some of them seem silly or useless, or else you will handicap your progress in other fields which you didn’t see the connection with at first.

Why mips and not RiscV? I would assume it’s easier to emulate in software and has good support in linux

EDIT: found it

Some architectures had arbitrarily-shifted operands all the time (ARM), some have shitty addressing modes necessitating that they would be slow (RISCV), some would need more than 4KB to even decode instructions (x86), and some were just too complex to emulate in so little space (PPC).

Could it be the pc relative addressing often used on risc-v would be slow to run on 4004?

It’s the other way around, you will get all of the tickets which are missing plate info. Some guy did it and regrets it, there is a documentary about it.