This is a great question. I've been meaning to put the time in to experiment posting into many, look for new ones, etc, and see how they behave towards "unknown website" links. This would then allow me to create some kind of list we can pin on @redditposh or somewhere to make it easier for users to know which ones are "friendly" towards sharing.
Wish I had more time or that more users would get involved in helping out, until then I guess it's a hit and miss/try your way through thing.
r/cryptocurrency seem to allow most posts from leofinance but it has to be broad content (i.e. not just something random about hive related). They usually have some random rules like "too many posts about coin x today so we deleted your share" etc, but no harm in trying as long as you don't spam or get banned.
Ok I will try to find something :)