I'm planning on trying JTB first and then if I'm not lucky I will also try Lawson's. We really want to see the museum so I will make any effort to secure tickets. To me, it's no different than trying to get FPs for Disney World.
I would say it's considerably harder to secure tickets to the museum on a given day than to get a FP+ for Pandora Flight of Passage. But who knows, I seem to remember mid May had better availability then some other periods. Getting a FP+ though is very different. You can keep trying through out your stay to change or add something vs. once the tickets are gone, they are gone outside of the 15,000 yen per person tour.
If you live near a JTB office, I think it is easier to secure tickets than if you need them mailed. Make sure you apply on the 1st and if you do not receive an auto-generated email back from JTB, it did not go through and keep making sure to apply or call to make sure you are in. Some branches can take phone requests and some can not. I would avoid the CA branch unless you can go into one of them in person.
If you stay at a hotel with a good enough concierge, they can book the Ghibli tickets via Lawson for you as well as the Pokemon Cafe. The Pokemon Cafe should be booked 1 month before your intended visit and again must be booked for a specific time. My Tokyo hotel just booked the Pokemon Cafe for me, and I am debating having them book the Ghibli tickets as well, since I bet they can do it.
And for anyone curious:
https://soranews24.com/2017/10/27/k...turns-into-rain-and-disappears-into-your-tea/
That's the Cloud Coffee place in Kyoto and
https://www.sweetyhigh.com/read/pokemon-cafe-menu-2018-030218
There is the Pokemon Cafe Menu, though I would't be surprised if they switch it up occasionally.
And speaking of Ghibli, there is also of course the Totoro Cream Puff Cafe owned by a relative of Miyazaki's
https://fastjapan.com/en/p131869