I don't know about IOS, I can't see a reason why it wouldn't work.I also would like to know this. I have IJE0S_UserChannels.xml AND UserChannels.xml (both because I wanted to find out if removing IJE0S would work) in the MHD root directory, but see no changes. Does this xml config file only get picked up on Android?
The format requires the ROM version at the start of the filename. MHD looks at what ROM you have, then checks the root directory for the additional parameter file for that particular ROM.
I don't know the best way to keep track of these parameters on the forum. Ideally we would have a wiki style repository that would let me enter the parameter name, description of what it means, scaling parameters and then the address for each of the 4 major ROM variants.
I could also find the N55 ones if nobody else is already doing it, it would just take a little more time as I'm yet to disassemble any of those ROMs.