Affinity Photo still complains about unkwon ressource blocks it doesn't know and simply stops loading. If a future Photoshop version adds a new tag - the same will happen. This behaviour throws the whole forward and backward compatibility (that is so great about the PSD format) out of the window. As far as I know the PSD format was intentionaly deisgned to not have versions, but features. There is no reason to halt import because of an unknown ressource block.
Detailed bug report here:
https://forum.affinity.serif.com/index.php?/topic/30366-psd-parsing-bug-import-halts-on-unknown-image-ressource-blocks/
BTW, thanks for quickly fixing the other bug I reported (32-bit PSD layer mask).
Daniel