I don't know about specific communities but I have noticed that often smaller seed companies include stories about where they get there seed from. I suspect they know more about where to find large scale plant breeders than anyone else will.
If you have
local garden communities that engage in seed swaps that could be a great way to meet smaller scale gardeners who are just sharing the few extra they aren't putting back in their own garden.
I ordered seeds from True Love seeds this year
https://cdn.shopify.com/s/files/1/2406/3467/files/ttrueloveseeds_logo_textpic1-crop-600w_1080x.png?v=1510372098 and they're a good example of those farmer descriptions. They may be focusing on preserving varieties but I don't think you grow tropical vegetables in New York without at least some adaptive selection.