[finishlast]

Not sure if I understood you correctly.
You want the smoker to "punch" survivors with the tongue but not pull them back and deal damage with only the tongue punch?

I made a plugin behaving like this:

Setting down tongue delay on miss to 0
Then cut tongue on grab and add 10 hp damage.

With the cooldown being 0 you can attack right away.

cvar for delay between punches
cvar for punchdamage

If you make this plugin act random per smoker spawn you could even create a second type of smoker along with the normal with this.