Closed ring device in Brummel splice

[Bott]

As I see/understand it, you have a few options.

It sounds like you are making the splice in the "mobius brummel" fashion, like the howto on Colligo Marine's site. That has the advantage of not needing access to the other end of the line to make the locking tucks, but you have to form the eye "in place" and cannot splice it around some closed object. like your ring fitting.

You can keep the mobius splice and cow hitch the loop through the ring, but you'll be putting the line through a decently tight bend to do so which will reduce the strength in that area. You'd have to run some numbers to see if that is a compromise worth making.

Alternatively, you can make the splice in (what I understand is) the typical brummel method, which requires access to both ends for the locking tucks, but you can make around a closed object. Its a great splice, but can be a pain with long halyards or when trying to make one "in the moment" for a repair. Doesn't sound like that would be much of a hassle with a baby stay. You'll probably have to wrestle out the thimble from the first end for the tucks though. One of Mr. Toss's little splicing books (#5?) has detailed instructions for these.

Just my observations and experience.