Re: commercial lockout
"This would turn China into the centre of development for RISC-V and could quickly lead to Intel and ARM becoming also rans."
I think you're a little optimistic - RISC-V and MIPS are not too dissimilar in terms of being freely available CPU designs with MIPS having the performance advantage and RISC-V having the tooling advantage.
If you integrated many of the performance enhancements found in the MIPS design into RISC-V, you would likely be able to compete with a current high-end ARM processor but it would likely take 5+ years to get the design validated and on the market by which point your competitors are another 5 years ahead. Plus you need to develop your tooling at the same time AND make some money.
That's not to say RISC-V will not be successful, I think it will - just not to the point where it can challenge ARM let alone Intel or AMD.
If you were instead to look at ARM/Intel/AMD making mistakes that cost them their positions in performance or market share, then there is a much greater opportunity there. Advanced CPU designs are complex and expensive, particularly when you make mistakes.