One further thing, I found by changing Terminal=false to true, then a terminal window will popup asking for a password, enter the password and it works.
So only conclusion I can draw is that it must be permissions related.
I'm the (proud??) owner of such a device but I prefer the Pie
What I meant - since you have one - maybe you can find an equivalent program to raspi2png for the Droid and be able to test it (not create one from scratch). Something like fbgrab or fbdump maybe.
@steve-bamford yes, sorry my response was a bit quick! I must have skimmed over your question. It's good to see others using xroar. I use it to play the 5 games I had on the Tandy 30-odd years ago.