So … use RISC-V as the strawman, and create a community-based RISC-6 that doesn’t have these weaknesses? Better to get in now before it becomes too solidly entrenched.
Likely impossible unless you somehow come up with something vastly better (unlikely).
None of these things are remotely bad enough to make the downsides of using another ISA palatable.
You can't make a community-based ISA, it's not possible unless you have a community-based fab. He who makes the chips makes the rules.