This was all on a fresh clean install...
It seems I somehow sorted it out:
Went hunting for BIOS roms and installed all the one I found (even and especially the optional ones).
Additionally I also slightly overclocked the pi zero (though I don’t believe it had direct effect on the freeze issue; makes it overall run better though).
So far I don’t experience the same issue anymore so I believe it was due to the fact the pi zero is a bit limited in computation power so it really need BIOS installed (even optional ones). or so it seems...
Thanks for the feedback though! Very much appreciated!