Some questions from a new hanger

Hi there guys, I hav PE serious since march and today I began a haning routine, the one in “hanging 101”

I hanged 3x20 min with 1kg (a little more than 2lb) in direction SD.
I have read that you should change angle after 4 hours, is that important? I think SD feels good, would it be a bad idea to keep hanging SD all the time?
And if I wish to change angle after 4 hours, should I hang 4 hours in that different angle and then switch back to my original angle? I have read pretty much about hanging but I just haven’t got that figured out.
And which extra angle could be good for a newbie? I have read that BTC is..

I have been hanging since May just BTC but I think I will start doing some SD. From what I read you maximize your ligament stretch within 6-9months I think there might be a few tests for that and then you work on different angles to stretch your tunica. I do 6-8 sets I was doing 5-days a week but not I am doing it everyday without any time off

Ok so you only hang BTC and never switch angle?