If i was going to try a variation on Ron's plug mod, it would be a Lehigh domed vent was installed just below flush with the powder side. This would only shorten the flash channel a small amount in the OEM plug and the domed vent could not possibly damage a pellet.

A short jump from the vent to a pellet should not be a problem. Look at the old Knight CrossFire plug made for pellets. The distance was much greater from flash hole to pellet.