It is a real pain to try and obtain every piece of knowledge from a specific category when it requires you to do/complete a specific quest or questline, since you don't always know where that quest is, how to unlock it or what parts of that questline you already completed (maybe by accident or other reasons).

Tools like bdocodex already exist which serve as a similar tool to having a dedicated entry in the quest menu, however those third party tools are not perfect and are very tedious to use in cases where you already completed a questline partially. Running from Quest NPC to Quest NPC from that questline, taking multiple trips back and forth and possibly not even finding the quest because you're missing a requirement is very annoying and demotivating.
Just recently I had to send a ticket to the support because I spent 3 or 4 hours trying to find this one questline that unlocks a Calpheon Adventure Journal knowledge entry. In the end the support guided me to a quest that wasn't even present in the questline on bdocodex, so if I hadn't messaged support I could have searched for that questline for another 100 hours and never found it.

My proposition then is to have a dedicated tab in the quest menu for quests/questlines that unlock knowledge or dialogue options that unlock knowledge.

Maybe to not have 300 collapsable entries in the tab have them inside entries per Journal. For example one collapsable entry is "[Balenos] Velia Adventure Journal" and if you expand it it contains every quest/questline that gives knowledge in that category. And then have another entry "[Balenos] Iliya Island Adventure Journal" and another "[Kamasylvia] Kamasylvia Entrance Adventure Journal". Or if that would still be too many entries simply have 1 entry for each region instead.