Those of us that change planes as frequently as we change socks, do you have a registration for each plane or take the same one with you?
Also when changing plane in the FS hangar, is the registration specific to each plane or does the sim just hold one reg?
Just trying to tidy up my sim life a bit 
I’ve set it fixed. Don’t really care about it and when using vatsim it’s nice to be used to the same call-sign.
Same registration for all GA Flight, Airliners I use the real world flight numbers.
I like to have different, personalised, registrations for each aircraft in my hangar. I also like to use add-on liveries but unfortunately most 3rd-part devs don’t provide that feature in their products, which frustrates me. I know you can “change” the aircraft registration in the aircraft.cfg file but if the dev has “baked it in” that doesn’t work and I’m not going to learn how to make liveries so that I can change it myself - not THAT keen!
All the “stock” stuff works okay though, including editing the aircraft.cfg file.
VATSIM user with a bit over 6,700 hours on the network. Unless I am using a livery that has a baked registration I change it somewhat often however all of them are valid and assigned to the make and model I am flying. It bugs me personally if it’s not. I’m not one that sticks to just one personal registration for everything and I don’t think I ever have been. I have ran across a number that do though.