I’m wondering how successful is getting users to tweet to the providers of those you cannot support yet.
If it’s very supportive that’s good but not everyone has Twitter and some people may actively choose an account you can support.
Therefore, how about a toggle on the new accounts lists to hide unsupported providers currently? By default it would be toggled off so it won’t look like a shorter list when browsing and you could include a tooltip to make clear what it does?