Change each one to .5x in order to bump up the animation speed. (Smaller numbers are faster, larger numbers are slower. You can also turn off animations altogether, but that's not advisable as things look very strange without them.)
an oldie but a goodie
while you are in developer settings you can also set how many devices can connect to your bluetooth
default is usually set to 3 devices
you can change that to 1 or 2 depending on your needs
in dev settings look for "maximum connected bluetooth audio devices"