I don't think this is really a problem that the WASM standard needs to be too concerned about. Execution engines themselves should provide ways to preempt execution. I'm more concerned with these proposals that they are introducing a lot of complexity to implementing WASM.
> Execution engines themselves should provide ways to preempt execution.
Yes, and that preemption occurs at the opcode level. Which is completely defeated if your string matching opcode can hang for an inordinate amount of time because the user supplies a very large string and/or crafts string inputs that force O(n^2) or worse behaviour.
I implemented a WASM interpreter recently. Didn't know WASM when I started. GC wasn't particularly difficult. Type canonicalization was the trickiest bit. Did a small subset of stringref, too. If there's anything I'm intimidated by with WASM implementation it's all the SIMD instructions.
