Well you can't downgrade it seems (NSU simply says I have the latest for my real product code - in fact I have newer than the available latest). I've tried a few different codes including some branded ones. They do appear different in a few ways (fonts were different on another generic one I tried). Also I found Roadsync wouldn't do push properly either on one version. So maybe there's more differences than you think under the hood.

I also found a few mentions that if I tried to force it with tools more like NSS, I'm likely to brick it.

So I either have to wait for the v3 to come out for my product code (which I doubt will make any real difference) and just live with it as is.

I'm going to give it a run with the product you used sein (0530151) assuming the keyboard lines up.