I found this video about HU ranges
https://youtu.be/_-AiqRpio20?t=297 , however it's HUNL , are they ok to study still for SNGs ? Because this website deemed as good
https://www.pokersites.io/heads-up-poker/ doesn't really treat 4bet sadly (unless i'm blind which is possible too).
I've decided to practice a bit before jumping to Spins (also i fell in love with heads up too )
Thanks!