I replaced the rubber bushings with 3/8 neoprene washers from the plumbing section at Home Depot / Lowes, etc. The hole is just the right size to fit over the T-Nut that sticks through the front of the holster. This eliminates the buldge significantly, but still allows enough spacing for "tucking".
I also cut the excess length off my clips once I determined exactly how long I wanted them. This does add to comfort. I did this by first cutting through the hole just below the one I wanted to use (with my band saw). Then I attached #6 x 3/4" fender washers to the hole I planned to use with #8 screw & nut (1/2" long). The washers straddle the clip on either side of the hole. I then used a belt sander to remove the excess clip material. The washers limit how much of the excess is removed and give a perfectly curved end. Remove the washers and take the sharp edges off the end of the clip (front and back) with a few quick swipes by hand with fine sand paper.
I have also modified my M-Tac with a new leather body to meet my needs for appendix carry for my G27 with Crimson Trace to make things more comfortable by keeping the gun/laser totally away from my skin.