I’d like to be able to see and change the actual resistance level while ERG mode is active. So that for example in the desktop app the left and right keys can still be used to adjust the resistance level even while being in ERG mode. This would be handy for example to set up the resistance for an interval while in ERG - and then when switching to resistance mode (M key on desktop app) the appropriate resistance level is already set.
I use one gear with straight chain line mostly in ERG but sometimes switch into resistance mode for different intervals and instead of shifting I adjust the resistance level until the appropriate wattage range is reached.
Maybe you could show resistance and ERG fields at the same time with green border for the activated mode.
Extra bonus would be to have x different resistance level slots with own shortkeys.