Feeder envelope for using TPU on bowden drive

I am using this to print with TPU on Geeetech A30 with aluminium feeder.

To fix it in place, I used 5mm of bowden tube (see pictures), only about 3mm is protruding at the rear. Also, holes print a bit narrower depending on your printer/settings, small one at front needs to be expanded to 2mm (to fit 1.75 filament) and one at the back to ~4 mm to fit bowden tube.