so, i decided to follow a route that works for most fonts / cases and not some messy hybrid solution (and i don't want a different setup or bag of tricks for each font that is out there as that is a long term no-go)

But I have to contradict you here: It has nothing to do with special or hybrid fonts. The problem persists at present (using the LuaTeX version that is shipped with the Garden version) in all fonts. The primes are not rendered as they should in any font I tried out.

As Mikael told me, you optimised the code for LuaTeX 1.05 which seems to be terminated September this year. But until then the output of primes will be not correct. I have no possibility to switch back to the current (non-beta) version of ConTeXt, because this version contains the bugs with primes you have already resolved.

This means that ConTeXt is not usable for me until LuaTeX 1.05 will be released or until I am able to compile the source of LuaTeX 1.05 on my own. Some of the latest betas (the version one or two weeks ago) did solve all problems regarding primes. The problem I am referring to rose up in the most recent betas. As Mikael told me, this is because you introduced new code to work with LuaTeX 1.05. This is very nice, but because this version is not yet released, this decision is questionable, since this makes ConTeXt unusable until this release (if you need primes).

So I appreciate your hard work, but I would be nice to have a version that runs with the current LuaTeX version of the beta of ConTeXt (or alternatively it would be nice if instructions are provided to compile the source of LuaTeX for every OS that can be used simply).

And (to repeat myself) the problem has nothing to do with special fonts of hybrid version or whatever. You get the problem using standard Latin Modern or any font else. Simply try