Made a quick, vanilla friendly mockup of what sulfur springs should actually look like (plus a before pic for reference)

Tried to make this more concave than convex, like an actual sulfur spring (like the pools we already have in the caves), and not a mound of sulfur with a puddle of water

Features:

-2 block deep pool; relatively small (size variants would still exist; I just made this very quickly)

-Thick rim of sulfur by the water

-Thin outer rim of calcite (since sulfur springs often have calcium deposits; calcite should probably generate in the caves as well)

-Excessive glow lichen in the water to reference algae/bacteria that create "green sulfur" (already sort of referenced in the actual caves)

Built this in a desert because that's where the nearest spring in the first seed I picked was at, but even this design I slapped together in not even 20 minutes would blend in to grassy biomes way better than the awful "springs" we have now

Sulfur cave here