WieWaldi I don't want to spoil my muscle memory. I think it slows down the progress.
Maybe... but I think any brain can learn to handle both. Just like we can switch between auromatic car and stick shift. Or between acoustic guitar and electric (different size fret board, different angle, etc). And then switch to bass guitar (4 strings, different attack). Awkward at first, then it becomes normal.
Of course, if there is no need to switch keyboards, then it is better to put the energy into more useful things... such as Hanon type blues licks