Variable name subscripts in Prime

Now that I have been forced onto Prime (changed employers, new install, 15 no longer for sale) I am really struggling with the keyboard shortcut for subscripting variable names. I get that there must be some good reason why PTC couldn't use . (period/dot) for it any more, but seriously "ctl -" is about the worst possible key combination they could have come up with instead - diagonal opposite corners of the keyboard making it a difficult one handed combo with lots of scope for mis-pressing one of the 2 keys and ending up creating some nightmare instead of the variable name you intended? I know word uses "ctrl +" and "ctrl shift +" (or something like that) for this, but the whole world doesn't have to follow microsoft's mistakes blindly.

Please please please give us a single key shortcut for subscripts in variable names - is there somewhere we can start a petition of something to lobby for this? I am wasting hours and hours of time going back and re-typing my variable names because I have added a . or _ without a ctrl or even a boolean =, all because of this stupid "feature" in prime and deprecation of version 15. It is currently negating any benefits I might otherwise see from good features like linking workbooks.