Some insights that I hope will prove useful.
1) In the last days of the war, anything that could fly was used.
2) Transport flights usually means something was dropped to defenders on the ground without any order in writing. I have read about supply drops but how these drops were accomplished using fighter aircraft is not specified.
3) Some late-war aircraft were photographed with numbers spray painted on the fuselage. This suggests ad hoc units formed to do specific things. Much like the Kampfgruppe in the Army that took whatever men they could find to create "irregular" formations the enemy would not expect.
4) Pilots with more training were generally used to improve the odds of survival.
More information:
https://www.asisbiz.com/Luftwaffe/sg103.html
Ed