I believe it is spelled, "soluble"...
When I embroider (with my machine), I embroider the fabric, then put it into the quilted project as if it were any other piece. I treat it the same as if it weren't embroidered. I do use stabilizer. I usually use an iron on (permanent) stabilizer if it is something I want to really keep its shape.
I also use tear away stabilizer that stays just where the design is. The rest tears off around the design. I use the tear away most often bc I can't seem to get the iron on kind to really stick! ? I don't know why.
Well, now you have my two cents on that one.