I think adding saving throws for Burning/Acid statuses would be a good middle ground. Dex on Burning and Con on Acid would probably make the most sense to me. Would also make Acid less scary for tank/frontliners who probably have high con and/or proficiency. Although you could argue that once on fire you should make Con saves similar to Heat Metal?
Apply these effects on stepping onto a surface.
different saves for same effect feels weird to me for a 'simple' cantrip.
It came to my mind that turn timing isnt a thing outside of combat in bg3: on tabletop a round takes 6 seconds, naviganting thru a dangerous surface should force a save every 6 seconds instead of every 5 feets like now. This would make traversing a room on fire less deadly. I would also argue about a dice of direct damage of fire surface along a dice of fire proc seems too much: as of 5e a torch smacked at you or stepping into a fire camp awards you 1 point of fire damage on the spot
