Yes, that's true. It's a balance to find between RAM and speed.
I was thinking more on use cases that require to disable JIT anyway (WASM, iOS integration, security).
Yeah, could be nice to allow the user to select the type of ECMAScript engine that fits their use-case / performance requirements (balancing the resources available).
If your target is consistent enough (perhaps even stationary), then at some point "JIT" means wasting CPU cycles.