Thank you for those links and for all the research you did. I read thru all of it, you appear to have come to the same conclusions I came to based upon the same lines of reasoning. I chose a different retailer based out of GER vs England.
I did pay attention to alamos_kiter's constant coomentary on abrasion, however given the fact I am stretching all of my lines to the 9s, never drag my lines, and wash my lines after each use, I believe abrasion is not the chief culprit.
Design wise, I am flying Naish Torch with Shift system and Fusion 5 line bars - both of which use a high Y split where the two flying lines connect via a heavy duty Y connector to a single lower line that runs down to the bar (eg all of the power of the kite is coming down via ONE spectra line). Naish uses sub-SK75 (something weaker than SK75) and has not updated their LINES (not the bar, the line material) in years as comparing their latest bars the line material is identical lines from years ago. Liros testing article stating breaking strength of 240 kg confirms my real life experience of stretching out Naish lines in less than a month and breaking my flying lines often at 110kg riding in 30-50 kts (Maui and Cape Town) throwing loops. I recently cannabalized a Slingshot bar with those heavy duty center lines and used those to create a custom bar for my Torches using SS lines and a 2013 Shift system (straps, 5th line, and QR/CL). That bar is what has kept me riding while my Naish Fusion and Shift bars all keep getting broken, repair after repair. My conclusion is I need better lines and its not all abrasion given the major stretching problems I am expeeriecning. The DESIGN of running all of the power thru a single line requires a heavier duty line on that lower section of the flying Y lines than standard DYneema. Q-Power Pro looks interesting but again, at 275 kg breaking strength, I want something stronger for that lower Y section. I do understand what they say about the tight weave not letting in foreign material - it would be a dream if they updated their lines with the newer sk-99 and went for a heavier duty version. Shame, I contacted kiteboarding.com but thery never responded, as is I am importing in two spools of Liros dc-401/301 and will have to pay someone on Maui to finish my lines.