I’ve found that slowed down even to 75-80%, most songs still sound good. Below that, not so much. I’d imagine that 65% would sound kind of ridiculous on pretty much any song.
Random selection to see if it worked and a tongue in cheek comment. Life is just too short.,
Oh yeah, that’s the way I took it!
Try using a metronome and do repetitions and sets of the switches, just like you would do in gym.
Put the metronome at the slower tempo you are able to make the switches and if you can reach your reps target - let’s say 10 consecutive switches without a mistake - se the metronome a bit higher.
If the metronome is too fast, do the switches as slowly as you can without the metronome, until you are able to get to a speed in which you can use the metronome.
But before you do all that, make sure to pay attention and recognize what is it that makes a particular switch difficult for you, in order to break the switch even further and make a specific exercise out of it.
For example, it might be a finger that needs strengthening or maybe a finger needs to be more accurate, etc.
Cheers!
Ted, I agree! Thanks for checking in.