Quick question before merging accounts.

So I got this ancient account from the old poe beta with coins still unspent, but the account I've been playing on via steam was apparently a different one. I followed the steps to merge them, and got no issues there but since there was some explicit warnings I just want to make sure wheter its worth doing so or not.

"

The Steam account associated with this request is already linked to another Path of Exile account.

Current Account: xxx

Existing Account: xxx

Proceeding with this request will permanently associate your accounts.

You will not be able to merge any further accounts with the same login methods (Steam) to this Path of Exile Account.

This action cannot be undone.

What's confusing to me is that the steam account is not currently linked to any other account? or rather I mean when I use the login method of steam on this site, that account has no associated email or anything. it does not have a primary login at all just the secondary steam login.

I'd also like to add that the steam account does not really have any significant value, just some achievements and my old characters, but no monetary investments so going into PoE2 with my old unspent coins on this account is more important to me than the sentimental value. With the servers about to explode with eager players, I'm just weary about the merging process causing any issues when it's not that important as of now.

Sorry for this long-winded message probably asked many times before. tl:dr is the merging process instant, or could it take hours, days. Safe to do now, or should I just wait a couple of days for when the dust has settled.

Well, what I'm after is using this account as my one account, which I want linked in steam as well. But save whatever old characters & achievement progress I made on my current steam account first before doing so. There is no micro transaction involved, so if both accounts become sub-accounts will that mean I have to create yet another new main account? or will this account only be a sub-account in name only and still remain as my primary login.