How do you decide how much extensibility to build now vs. when the 2nd/3rd collector actually shows up?

**Constraints, for context:** cross-platform (Windows/Linux), vendor-SDK-gated (don't build a collector if its SDK is absent), hot path untouched (producers only push to a lock-free ring; all heavy work off-thread).

Thanks — happy to expand on any part. Mostly after "here's what you'll regret" and "here's the boring standard way to do X."

https://redd.it/1u71mfb
@r_cpp