Nah, doesn't really matter where your account is really. It's just that the communities you're wanting to post to might be in other instances. You can keep the account here and post to those communities just as seamlessly.
And I second the notion, would like to see more of you here.
No worries, it took me a bit to really figure out myself when I first joined a few months ago, and I've been in IT for almost 25 years lol. But yes, what the other person said is true of all instances, you can see the different communities of other instances that way and subscribe, post, or comment as you want, even if your account isn't there.