Level Cap to turn in NM Shiro books

I couldn't see this question answered here or on wiki, sorry if I missed it. Does anyone know if there's a level cap for turning in the normal mode shiro's return books for kurz/lux faction? The eotn reps stop taking nm books at rank 8 I believe, then only take hard mode books, but rank 8 in the kurz/lux titles is only 1/4 of the entire title. Anyone know?

I don't think the Kurzick/Luxon NPCs stop taking NM books at any rank, same with Lightbringer. I think Sunspear stops at rank 8 (where you can't get points via bounties in NM). I do know there is a minimum to when you can turn a HM book to Sunspear/Lightbringer, but I don't think there is any requirement or cap for either NM or HM books turned into the Kurzick/Luxon NPCs.

I don't believe there is a limit on kurzick/luxon from the factions handbook. lb is r5, ss is r8, eotn titles are r8.

There's no mention of a cap for this. I'm gonna go out on a limb and say there isn't one.

Here's why:

The LB, SS, and EotN Title tracks are character based, so whatever books you get & turn in will count towards that character. The Kurzick/luxon titles are account based, so it's a cumulation of whatever progression you now achieve with all characters.

Also note that you can continue to contribute to the Kurzick/Luxon titles in normal mode no matter what level you are. The Blessing of the Kurzicks/Luxons doesn't stop being available once you reach a certain rank in the title.