I have avoided certain authors because they've hit my DMs like: "omg your stuff is so great, will you come read/comment on my stuff? You're popular so it would really help me out"
First of all, I'm not that popular
Second of all, nah. So, I couldn't say if they were promising or not.
Though one person did get very upset with me that declined collaboration with them and they told me I was being selfish and I didn't want to share the spotlight and help smaller creators. It was bizarre.
And I did block an author on Tapas because they were starting to be creepy. So I did drop their series as a result of that.