I appreciate the responses and information.

It seems the consensus answer to my question is "no." That's useful.

I'm going to start poking around for simple 18650 headlamps. I've been playing with the raw/unprotected ones for years, charging them directly off a 15W solar panel (monitored closely) and running old LED lights directly. They do seem to be better in many ways. We'll see if the protected ones are as good -- I have a charger on the way.

But all this belongs in another thread.