Taipan Vet owners with the power plenum

( . . . Ernest Rowe thing I believe it is?) Well anyway - Tony @Talon Tunes has (had by now?) some and I grabbed one. Question - the Taipan's have an aluminum plenum / spacer just behind the reg where the air cylinder threads into the action. For those of you who have one of these - is that aluminum tube still required or does the power plenum completely replace it? ( if the latter . . . then what prevents air pressure from pushing the reg down??? ) Maybe I need to go to bed and stop over thinking everything @present . . . ( I'm tired ) lol . . .

. . . reckon' I'll find out when the thing shows up.