must be some serious Belvilles in that tube .... I'd assumed it had to be something to do with the lateral articulation, by its position, each end
used to have a 10ft x 1/8" Morgan truecut guillo which had Belville stacks each end for the return and hell did it ever jump back up from a full stroke cut .
My BIG Pearson 10ft x 1/2" had a nitrogen return system which was a lot more 'gentle' on the up stroke, even after a full 10ft cut ... the old N
2 was a lot more flexible/forgiving of being compressed