I've often wondered how do instrumentalists (especially accompanists) adjust to madhyama shruti ragas like yamunakalyani etc. Do they re-tune their instruments for the song or can they adjust on the fly? I'm not much of a live concert attender i am afraid

Do all madhyama shruti ragas compulsorily end at Nishadham?

In Veena Instrument, madhyama sruthi raga (yamunakalyani) is played from Suddhamadhyamam note, where M1 is taken as Shadjam. It would be very pleasing to hear a madhyama sruthi raga in an instrument. It requires great practice to play in veena, as all the note positions change when M1 becomes Shadjam.