I ordered mine from DiscoAzul, took 11 days to arrive after despatch, and the cart came running v1.19 beta, which ran fine on my 4.4.0 DS, and I think would be OK on 5.1.1.
Changing the 3d renderer from 'nocash' to OpenGL might get rid of the transparency artifacts at the cost of speed and possibly other graphical problems, but I can't check as I run no$gba through WINE and the OpenGL renderer just throws up an error when used.
Using NO$GBA + NO$Zoomer, with the original DS BIOS, I do not need to enter the AR blackscreen code and spent around 20 minutes going up and down the escalator in a Pokémon centre before getting bored and going off to actually play. No freezes to report in playtime either.