after posting and thinking about this last night, I tried to put all into practice today.

spent a while flying around at height looking for the "slowest" (use-able) speed and getting used to it...

I also did many touch-n-go´s with one PERFECT landing right at the start of the runway..
the finals were with zero motor, motor trimmed very low and not too fast.
I rolled the entire lenght of the runway.

Yes it is a tarmac runway.
the grass strips arent really an option as here in spain its so dry that the ground is full of rocks, not nice runway at all.... tarmac or nothing.

EVERY time I end up rolling off the runway and only stop when I hit the dirt "wasteland" at the end.

I´ll try your fuel tube Idea for next session and see how It goes, maybe on one at first and 3 if no change.