you can tune a piano any way you want but you cannot tuna fish.
pianos back when Bach was writing were not common, he wrote much of his stuff for harpsichord and organ.
There are organizations like the academy for ancient music that specialize in using period instruments and sometimes with period tuning. It sounds quite different.
I asked a random AI if you could do this with a modern synth and it said
Yes, you absolutely can and should tune a harpsichord to a Bach-period temperament (unequal temperament) to hear how Bach intended, using specific “recipes” like Vallotti or Kirnberger, rather than modern equal temperament, which makes keys sound distinct, but it requires specialized apps or tuning by ear with a tuner for those specific intervals, not reprogramming electronics.
Digital keyboards can often switch temperaments, but a physical harpsichord needs manual adjustment for each string to achieve these historical settings, following patterns that vary by key.
“he wrote much of his stuff for harpsichord and organ.”
Aren’t those tuned more-or-less permanently like a piano.
I know the common even-temperament scale is a compromise, but it is extremely close to perfection in all 12 keys. I don’t see any value in a 12-tone scale tuned, say, for the key of C.