Sabotloader and myself have done it I have done 3 know and am delighted with the results. I now believe that the vent liners improve the consistency of the group or maybe it is the way we are installing them. I was working on the idea of making one and putting it in a couple years ago. Mike came up with the idea of drilling the hole the size needed [a #21 drill] all the way through and using the harder Lehigh vent liner [I had used a savage for the only one I had done. For some reason this makes a difference on how much carbon is deposited. The fancy BP for the Triumph and the Endeavor are expensive. and the vent liners run about 5 dollars a piece and it takes about 20 minutes to install the first one then if you ever need to [they are much harder and more flame cut resistant than the original BP] only a minute to change.
Mike used a lathe I used a drill press with a milling table. The procedure is easy I believe I could do it with a hand drill and a vise. Jut drill all the way through with a #21 drill and tap the muzzle end of the plug with a 10-32 tap. I only put 1.5 to 2 more threads than needed I count the threads on the vent liner and I use the drill press turned off and turned it by hand for the threading. [This makes sure every thing is strait with the drilled hole.] I set it up for strait by putting a drill that just fit in the drill press upside down then using that to position the milling table vise before I locked the plug down in the vise.
Hope this helps. Lee