Adjustable 2020 PTFE Slider

I wanted to make a slider you can Print that will work on almost all types of 20x20 Aluminium profiles. It uses 4mm PTFE bowden tubing as the material in contact with the aluminum profile. It makes contact in 8 places (4 on each end).
The screws at the end adjust the pressure of the bowden tubes against the profile, by using ramps.
You have to adjust the screws to find a compromise between a wiggle free slider and friction.
The nature of the design requires pieces of bowden tubing of equal le