Ethercat random jitter fix

I was able to run 1.5.2 ribalda built on debian 13 on Papagno's hardware, OP are quick, and no perceptible grinding on a simple bench setup, with 0.9.5 linuxcnc-ehtercat sittner, This is not even the good PC hardware, it had 400ns of jitter, and the motors seemed fine, we will need to test better on the machine.
This was mostly to rule out kernel jitter, biggest culprit for slow OP is definitely ethercat 1.6.9
We (me and YangYang) have a refreshed 1.6.9 in the works, but not sure when that will land, squashing some bugs still, the code bases 1.5.2 riblada and 1.6.9 igh went in two separate directions, and they are hard to merge, will put best efforts in, then we will have a version for ourselves we can maintain ourselves, since igh is kinda of unresponsive and or uninterested, no clue...