Thanks for checking into this -- much appreciated!
I now have redirects for blog.cellio.org and medium.cellio.org. They're "unmasked" and rewrite to the native URL; I haven't yet tested whether "masked" doesn't. But presumably that would only get you here and any outbound links would turn into DW URLs, which would be somewhat inconsistent UX. I couldn't redirect www.cellio.org; that wants a "CName Record", which I suppose is where the hosting comes in. Looking into your recommended provider on that now.
no subject
I now have redirects for blog.cellio.org and medium.cellio.org. They're "unmasked" and rewrite to the native URL; I haven't yet tested whether "masked" doesn't. But presumably that would only get you here and any outbound links would turn into DW URLs, which would be somewhat inconsistent UX. I couldn't redirect www.cellio.org; that wants a "CName Record", which I suppose is where the hosting comes in. Looking into your recommended provider on that now.