Oops, I thoght you talked about the low A, but now have seen it was a high solo A to be tuned down to G.
The Innovation Braided have an aluminium wound solo A (as well as an aluminium wound high C) in their normal program. They work on changing to a chromesteel wound solo A, but I'm not sure if it is available right now.
Tuning down by a whole tone you get a lot less tension on the string, which might become uncomfortable. I woundn't recommend this on any string, except if you need to do this very seldom. I think it might work better on the lowest string than on the highest one. But you probably tried that by detuning your string which is basically the same as using the Hipshot Extender.
I never had a strange winding on an Innovation string and only one bad string that buzzed a lot that I got replaced. But there are many different DB string types made by Innovation, I don't know which type you may refer to.
If you want the solo A to be tuned down the best compromise I see is getting a higher tension string for the solo A (i.e. Spirocore) and mix it with a bit less tension strings below (depends what tuning you want there) if you want to keep them fixed at their tuning. That way the difference to the E or D next to the A/G is not too large, one time a bit higher, one time a bit lower than the other strings.
I never played the Belcanto, so I cannot help with relative tension to the Spirocores, but I think they might have a bit less tension (but not much). If you want to to stay with E/A/D on the lower strings, Spiro Weich with a Spiro Solo A might be a solution.