Would it be possible to do a fully blueprint safe version that doesn't include the combinator?

The lamp post istelf looks really cool.

But lamp post with combinator is perfectly "safe" too. Not sure what you mean by that word though.
I'll probably add blueprint serialization as well, shouldn't be too tricky with just one signal.

Fixed copying signal (or hidden combinator as-is, rather) to blueprints too in 0.0.3.

The selection boxes are different for the two entities (the lamp post vs. lamp data) so you can accidentally blueprint one rather than both, and the instant building in the map editor loses the copy-paste / configuration capability in weird ways [as a result?].

Very cute mod but the inconsistencies with blueprinting of the hidden combinators remain!

Yeah, iirc it can be done better in general, having in-game blueprint selection ignore combinator, but store/restore this trivial state in blueprint tags instead.
I didn't know about that hack, but shouldn't be hard to change, and without breaking any existing blueprints with these lamps.
Maybe someday, like if I'll get back to playing factorio after expansion.