It’s probably fine. However, I will point out that you have correctly surmised that both exist to address similar issues. Ki-fueled attack is there to increase the value of the ki round (now for four ki you cast fireball and punch!), whereas the remastered version gives you more ki rounds (now for three ki you cast firebal).
I wouldn’t feel the need to add in Ki-Fueled attack if I was bringing in a subclass replacement that explicitly handles stuff like the one you linked does. 4 Elements needs more total spells (this one doubles spell access) and it needs greater efficiency on ki (your pick handles this by using the rounded-down cost of "level N spell costs N ki instead of the rounded-up version where it’s N+1).
I doubt it will break stuff, but I think the remaster solves it good enough and a better way.
It’s probably fine. However, I will point out that you have correctly surmised that both exist to address similar issues. Ki-fueled attack is there to increase the value of the ki round (now for four ki you cast fireball and punch!), whereas the remastered version gives you more ki rounds (now for three ki you cast firebal).
I wouldn’t feel the need to add in Ki-Fueled attack if I was bringing in a subclass replacement that explicitly handles stuff like the one you linked does. 4 Elements needs more total spells (this one doubles spell access) and it needs greater efficiency on ki (your pick handles this by using the rounded-down cost of "level N spell costs N ki instead of the rounded-up version where it’s N+1).
I doubt it will break stuff, but I think the remaster solves it good enough and a better way.