For a color and size comparison, here's Deinostigma tamiana seed freshly dried. My phalaenopsis orchid seed is much finer still! It's literally like pollen dust.

A beautiful and exotic plant! I've always intended to grow one from seed but I know they can be quite large and space around here is very limited. Good for you to be contributing to the gesneriad society seed fund!

Yes, they /can/ get large but just like a standard African violet, only if you let them and encourage them. If you keep it potted smallish and aren't afraid to pinch it when it becomes leggy late in the season, the size is easily kept small enough for any standard AV shelf. More the concern is humidity. -My- humidity in the Deep South is pretty high, averaging 60 to 80% in summer, but dropping around 40% in winter unless I make it higher. 40% is just too low for this plant and as you can see by my photos, browned the leaf tips and made the leaves droop. It's a slowish grower so it doesn't bounce back right away. But man, I highly recommend giving it a try if you can lay hands to the seeds. Endangered species to top it off.

BTW - berries are tasty.