bowden contraints issue

[CooperGerman]

Hi,
I'm currently using the E-RV printhead version and find myself noticing some issues with the bowden from the hexnut to hotend configuration.

The bowden cutout seems to be 4.1 mm in diameter but in my observation several bowden tubes have a tolerance to their outer diameters (in my case i have some ranging from 4.12 to 3.98).

When the bowden is not correctly imprisoned and constrained by both front and back halves, it seems that as volumetric speed rises some material builds up inside the hotend's radiator at the interface between the bowden tube and itself...

In this case, the hex nut is slightly pushed upwards (which might lead to some issues later i imagine) and printing gets harder as this build up increases.

I'm currently trying to find some solution in order to prevent this from happening that does not require proper bowden outer diameter. I was thinking about closing the canal like on picture below.

Maybe this could also work with an insert instead of the nut that would help block the bowden inside of the part.

Do you guys see any problem with the proposed solution ? I'm going try it out and keep this issue updated as i go along.

[CooperGerman]

Update 1 :
I ended up testing the following set up

I added a cutout for a brasse instert and resized the bowden tube to 13.6 (ish).

The bowden pointed by the red arrow is used to let the blase slide onto it and is a 2mm long ptfe tube.

I've had no issues for now, i'll let you now if any thing changes.