I like the 6PX Pro, and carried mine for five or six weeks, with about one hour run time every night (mostly on low setting). It recently got replaced with a Pocket Rocket 8, but the 6PX Pro is still a very nice light.
It isn't a light that's easy to mod. The factory bonds the head to the tube with red Loctite, and the softening temp for that adhesive is 350°F or slightly higher. Pretty sure that a temp that high will do no good for the board or emitter.
The light can be bored, but a second problem (if using flat top cells like the AW18650) is that there is no spring contact on the rear of the board, only a small silver dot. The work around for that is to use a small neodymium magnet on the 18650 - I believe Lighthound & others sell these.
So far, no one has sent a 6PX Pro to me for boring. If that does happen, I'll bore mine first to make sure that there are no surprises.