nonsense ^
stump bucket is crazy handy to have around, even on a BX. While grinding is still my preferred method for stumps, the BX can make short work of small stumps, as well as digging holes for planting, and even scraping out a small trench.
I dont understand this place sometimes, people come here ask a question, then they are asked why they need such a thing in the first place, then are told why they can't.
Getting back to OP; I purchased that adapter from EA, it was dropped shipped from a company in Detroit and I received it in about a week. This was years ago though. I noticed no loss in capacity, and was really happy with the product. The conversion was easy.
Some folks on this forum told me I was going to lose a bunch of capacity due to bucket being moved out. This distance was less than an inch using the EA kit. I did a test with full scoops of topsoil before and after the conversion, I didnt notice any difference with topsoil or using the grapple. Except for being able to swap loader attachments in seconds.