I guess they only teach it to jedi masters

Mmm, don't think so. Jedi Master Yaddle was one of very few who could do it. I.e., you had to be very strong with the force. Most force users rather see future or use lightsabers. Also, Yaddle didn't sacrafice life force to heal. THAT is exclusive to Ep 9. (Sigh) I was writing a fan fiction for 2 years. Featured a giant snake, festival, force healing, off brand lightsaber colors... set between Ep 4 &5. Yaddle was force ghost... main characters were... Palpatine's son abandoned to start life as a slave (but he's older than Anakin) and another of the royal handmaidens of Naboo. Guess garbage now. Disposition of the last gen 2 & 3 clones never to be resolved in canon story.

Flex tape could

I heard flex tape fixed the Death Star!