But how do I know that I need more spacers? Or I have too many installed?
(93mm - (your measured BB external width) )/2 each side, remembering the preload ring counts for 0.5mm.
My BB width (outside of cup to outside of cup) was 90mm with a ht2 BB. So 93-90=3. I put 1.5 ds, 1 NDS, then nipped 0.5 with the preload ring.
Fwiw, I kept them and got a partial for the false advertising of the spindle length. I'll use them on a gravel bike.
And yes my spider is out of true, although not so bad it contacts the mech cage so it'll just wear out the chainrings if I don't replace it.