Actually, on further testing, it looks like there is in fact an issue with this method. It seems as though the coordinates of an on-screen tap get messed up. So, if I want to tap a button, I now have to tap slightly above it. So, it's as though the co-ordinates of the tap have not been moved along with the graphics. Everything else seems ok though.
Also, is it possible to change scale modes at runtime? I noticed that this seems to get set in MyAssets.hx. I've tried adding a code block that does this:
scripts.MyAssets.scaleToFit1 = false;
scripts.MyAssets.scaleToFit2 = false;
scripts.MyAssets.scaleToFit3 = true;
scripts.MyAssets.stretchToFit = false;
but this doesn't seem to do anything. I need to do this because the Scale to Fit (Fullscreen) mode is the one I need for most devices, but I need this small tweak to Scale to Fit (Fill) for others.
Alternatively, is there a way to change the behaviour of the Scale To Fit (Fullscreen) mode so that the shortest edge is stretched out to the side of the screen, rather than the longest edge.