@substring I figured out the N64 graphical glitching issue, the XU4 needs to have an polygon offset factor set for glide64mk2 to function properly.

I played around with it a bit and the following seems like the best settings:

If true, use polygon offset values specified below

force_polygon_offset = True

Specifies a scale factor that is used to create a variable depth offset for e$

polygon_offset_factor = -2

Is multiplied by an implementation-specific value to create a constant depth $

polygon_offset_units = -2

This XU4 is pretty sweet, it even runs Conkers Bad Fur Day with minimal slowdowns.

For the ScummVM issue as a last ditch effort I copied over the ScummVM executable from my Raspi3 (running 4.01 and replaced the version on the XU4 and surprisingly it worked! So there does appear to be something wrong with the version shipping on the 4.1 XU4 image (and the version on the 4.01 image is probably an older version as well I would suspect?).