Using a pen name has been a bit of a messy ride for me.
I started using my pen name two or three years back, and I was pretty surprised people knew me by it eventually, however I discovered that when it comes to art (which is what I do), people seemed to recognize my style over my pen name! (I’d get messages on social media not connected with my pen name asking if I’m [name], for example).
About a year into being a commission artist I began using my real name (Kip) on social media and in my galleries, sometimes mixed with my pen name and sometimes not (like on tapas).
My watcherbase caught onto my real name very quickly (even though it’s not immediately shown in many places while my pen name is, most people call me by my own name).
So when it comes to pen names, I guess I always found one as a bit unnecessary? I think your style will definitly walk before you, and using the same accounts will help grow a watcherbase in that way. I think people also don’t always assume they can find you under the same name in different places.
One thing I did find was extremely helpful in creating a watcherbase that recognizes you was, surprisingly, a mascot! Especially if they’re fairly recognizable. I got a lot of people who recognized me through my mascot, and he even got his own share of love, with fanart and such!
Anyway that’s just my own experience with the subject haha