I am having the exact same problem. I can no longer find the speed mods in metrics.ini (however, my friend can using the same exact version I'm running??? (latest)), and I can't find anything on Google solution-wise.
The folder you want to find is:
There should be a SpeedMods.txt, but if not you could create one yourself. As an example, file contents could be:
%APPDATA%\StepMania 5\Save\MachineProfile
There should be a SpeedMods.txt, but if not you could create one yourself. As an example, file contents could be:
0.5x,1x,1.5x,2x,3x,4x,5x,6x,7x,8x,C150,C250,C450,m550
Does anybody have any idea how to use added X and C mods for SM online because I am able to use the added mods offline, but I have no idea how to implement them for online use?