My solution? 8 different quests per slot. Upon completion you get 1 seal of your choice. They are repeatable, but you can't get the same seal twice from the same quest. The quests don't all have to be easy or quick or cheap, but they should be achievable solo and provide a reasonable alternative to NM hunting.
My reasoning:
The uneveness of the quests is what annoys me the most. Some jobs quests take 10 times as long each run as others. That's just not at all ballanced.
But even ignoring that, it's still ultimatley an unchallenging grindfest. Repeating the same quest over and over again is mind numbingly dull. At least with AF2 farming in Dynamis there's something interesting going on, and you're getting currency for your efforts at the same time. You feel like you're getting something for the effort you put it. But spamming a quest 100 times? 200? More? How is that remotely challenging beyond having the time in the day and patience to do it?
Even if you are complacent with the drop rates and alternatives, you shouldn't be complacent with how poor and lazy the design of seal quests has been. Some of them are very basic indeed, and lack any real substance. Travel to 3 spots on the map, click on ???s, report back to NPC. OK, the first time is interesting and you need to find a safe route and a couple of confluxes, but the 2nd time onwards all that interest is gone.
Really, AF3+1 is nice but it's not that nice. Not compared to AF3+2. For most people getting their seals is merely the first step towards getting AF3+2, which comes with it's own challenge. The effort of getting the seals for +1s is disproprtionate to the reward you get.

