Repeat/Always Active Advice

I'm trying to limit the amount of lag in an area by not having a bunch of Repeat/Always Active command blocks going all the time. My current plan is that when a player enters the area to activate the command blocks for that area with redstone and when they leave to remove the redstone.

/execute if entity @a[x=280,y=87,z=51,dx=0,dy=0,dz=4] run /fill 287 74 60 260 74 60 redstone_block

/execute if entity @a[x=317,y=74,z=63,dx=0,dy=4,dz=0] run /fill 287 74 60 260 74 60 air

My question is: Is there a better way of doing this?