I'd like to point out that this has been my advice for the Elemental Monk since before I even made my guide (and I think it's mentioned in my guide... that I... stilll have to... update)
But have you or your players actually used it In A game? I have. It worked.
I'm of 2 minds with Four Elements:
1) Simple fix: Reduce the cost of most, if not all, of the abilities. Grant more abilities. Grant some cantrips.
2) Complete rework: Use the Tattooed Monk prestige class from 3ed as a template. Add abilities that don't require ki. Add abilities that aren't just spells. Perhaps allow the monk to specialize in one of 4 elements, or allow them to switch between them like the Storm Herald barbarian from XGtE.
I think it needs a total rework to be honest. Starting with something like:
"You are a monk of Fire, you learn the Produce Flame Cantrip, which uses Wisdom as your casting stat. Additionally, Whenever you use Flurry of Blows, you can cause your fist to light on fire, which causes all of your unarmed strikes to deal fire damage instead of bludgeoning damage."

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.