I think the countersunk M4 x 6mm and M4 x 10mm screws are badly spec'd. They are uncommon sizes and don't give a lot of thread engagement in the design IMO.
I've just assembled my G1000 frames and found 8mm and 12mm (respectively) to work better. I wasted a bunch of time cutting down screws to 6mm and 10mm since these are not very common sizes. Turns out i should not have bothered.
I haven't put together the GMA 1347 yet but i see it also spec's M4 x 6mm screws, and this time it looks like 8mm won't fit. Can i suggest increasing the thickness of the encoder backing plate so 8mm will do? 6mm are hard to source.
Hope this helps someone!
Agree, found the same issue.