I just made an electric wrench. I immediately tried to change it to lossless mode after charging it, but it did not work when I hit the 'M' key which the keybind said was correct.
I looked at the wiki. It says hold 'M' and right click. I did so. Nothing happened. I searched the forums. Someone had success in changing the hotkey. I did. No success.
I tried wrenching, then using the hotkey plus right click, then wrenching another machine. Both wrenched successfully, but without any increase in power consumption.
I have no idea if the mode was taken out, or if it is entirely malfunctioning.