Allow configuration of static props

Promoting this to 'beta blocker', because this requires an interface break. (Specifically: widening some return value of getRenderer() and possibly introducing another interface.)

@roderik: let's mark getRenderer internal and do it later?
I don't think we should postpone the release on this.

OK. I'll make sure to do this, when getting to this issue in kind-of-roadmap-order.

This now pretty much depends on [#3472359:].

Marking getRenderer() internal is one of the 'sweep up tasks' in 🐛 Update path and documentation Active .