The one with Puia is gone from my menu, it disappeared after I did the one with Techthon. Went to her to double check and it is not there. So my character has 70 slots (with value pack) rather than 71, so there is one little block on that row locked.

If I were to do the one with Puia first, the one for Techthon would have disappeared instead. 

Edit: Went on a different character and picked up the Techthon quest and the Puia quest is gone for them too, when I forfeit both quests reappear in the menu. Went to Puia, no quest. 

Same with claas and jarette quests, you can pick only one