SUTTON M14 X 1.5 Carbon Hand Tap - Bottom M2061407 | Total Tools
After a quick look I’m not sure how much there is to gain there. Looks like the thread stops 2 or 3mm before the bottom of the hole. I think bottoming taps chamfer is one and a half threads so even after running a bottoming tap through the effective, usable thread will stop 2.25mm before the bottom of the hole (1.5 x 1.5mm thread pitch = 2.25mm).
I’ll measure it up properly tomorrow and see what’s what for potential gains.

