Newly realized sensory here. I both wonder and desperately don't want to know how you feel. I don't think I could even function if I couldn't have a separate mental manual/muscle memory for each app.
Some people even have muscle memory for different keyboard layouts at the same time!
I know I used to switch pretty seamlessly between US International and ABNT-2[0] but others use Dvorak, Colemak and what have you which is obviously orders of magnitude harder...
I had a totally bizarre experience when I tried learning dvorak and gave up halfway. I found that it temporarily broke my ability to type at all and I became computer illiterate for a day. It was quite surreal. Some months later I learnt Colemak instead and found I was automatically keyboard-bilingual. My brain must have done some rewiring from my first experience. Now I can touch type naturally in Colemak, and still roughly type in qwerty (I learnt colemak because I originally sucked at typing and wanted to start fresh.)