@Vanitas Just my opinions, feel free to disregard.
If you switch from D to R, it looks like momentum for the R side. It will be used to say 'look at all of these people that knew we were doing the right thing and switched to R'.
It won't let you vote in the D primaries, and there might be a candidate that you wish to choose over another and that would kind of deprive you of that choice.
Those are really the only two arguments I can come up with. If you were Ind, it kinda won't hurt anything?