If you are on FB, I just found, a couple days ago, a group called
Worldwide Eriocaulon Owners. There aren't many posts, but scrolling back there are people who grow from seed. Might be a good source for info. People also post some about Synogonthas.
I didn't realize how many Erois there were and that we don't have here in the US. It will make you drool for sure.
It might just be one of those groups where people are not selling/selling hint hint, but it's fun to look at. Most people seem to be in Germany.