Alan , how much inward travel do you think you need? There are inward travel adaptors that fit into 2" focuser draw tubes, they are recessed so that EPs sit inside them. I have one made by Televue, sold by Bintel. They don't provide alot of range, maybe 1cm.
Another thing to look at is the mirror cell and its attachment, longer springs and bolts can be used to move the focuser up in the tube; you should not have to cut the tube.
Also there are a number of very low profile focusers on the market, designed for this type of problem.
Have a look here at one example:
https://www.firstlightoptics.com/sky...d-focuser.html
And another here:
https://agenaastro.com/antares-low-p...ual-speed.html
TS has them as well.