Except that's not how it works? Chip manufacturers just care about selling chips, not about being in the iPhone or being in an Android phone. It doesn't matter that some chip works in OnePlus phones, if it doesn't work in Samsung phones Samsung's not going to buy it.
If broadcom says it's going to be expensive to fix, either you pay or you don't. But it has nothing whatsoever to do with "controlling the whole stack".
As an aside, and it's totally irrelevant to the above, but there's nothing other than the amount of work involved preventing Samsung writing their own bluetooth stack. They write plenty of custom drivers and they created a folding device prior to OS support. If they wanted to they could; they just apparently don't think it's worth the cost.
Edit: according to a comment down thread they have done exactly that.
If broadcom says it's going to be expensive to fix, either you pay or you don't. But it has nothing whatsoever to do with "controlling the whole stack".
As an aside, and it's totally irrelevant to the above, but there's nothing other than the amount of work involved preventing Samsung writing their own bluetooth stack. They write plenty of custom drivers and they created a folding device prior to OS support. If they wanted to they could; they just apparently don't think it's worth the cost.
Edit: according to a comment down thread they have done exactly that.