Slitherine

I got OOB: Pacific, download version, from Slitherine. This is the version I have installed right now.

I did register it, redeemed a Steam Key, and used this to activate the game on Steam as well.

But do I have to dl it completely again to get it into my Steam Library? Looks like it wants to dl fully again from Steam for this, or is there a way around this, since actually the files are all there (I thought)?

Also, in case I do the full dl from Steam, does this mean I get quasi a second installation (from Steam) additionally to the one I did from the version bought at Slitherine?

I'm on Steam for a while, but actually don't use it that often, so I'm not really familiar with it...

Yes, bebro, it's basically like if you are installing another game.
They only share ...\Documents\My Games\Order of Battle - Pacific area for saving games, settings, modding, etc.

As they share most of the files, you could combine both versions, but it wouldn't be an easy process, as the main exe file is different.

I see, so I assume I could remove one installation (or not doing the Steam one additionally to begin with)

Thank you for the swift help

If you are not interested in the Steam achievements, then you really don't need the Steam version.