Problems creating and removing light

Maybe try to add a "on block tick" procedure for the air block that checks if the player is inside of it, and if not it changes itself back to normal air?

Create a block with invisible texture called like "lamp air" that emits your light, give it an "on block tick" remove block (make sure to not have particles).

To optimise the mod and make it less laggy you can add 1 to a local var that say "if local_var_name is =< 10 (20?) remove block else local_var_name = local_var_name +1" Then the block will not be removed every tick but each 0,5s (or 1s).

You can make the "lamp air" block spawn on x y-1 z to make it more "realistic" because your item is in your hand, not on your head :3

(And before placing the block, check if there is air on x y-1 z or you will have problems with plants, lava and water :P

Ok I tried and I have the same problem, now I see the meaning of your post, I'll work on that.

This is a delay/lag problem. The game can't calculate fast enough to remove the block at x y z because we aren't anymore on theses coordinates. You should check a 3x3 zone with "if block at x y z is lamp_air, remobe block at x y z" (and same thing with x-1, y-1, x+1, etc, etc...) then we can't miss any lamp_air block. I think there is a better optimised way to create a lamp but if you check a fairly large area it works.