Re: JB in a Hollowbody
Depends on the hollowbody.
On some, they will feedback no matter what you do. There are things you can do to limit that.
I have two fully hollow Corts. One has a JB and it does just fine, sounds fantastic, and the only feedback is nice controllable infinite sustain.
On the other, even a PAF made it howl badly, with a totally clean tone. I was able to get rid of a lot of that by 1) using rubber tubing instead of springs to mount, 2) putting foam between the bottom of the pickup and the back of the guitar, 3) putting a very thin adhesive foam I got at Hobby Lobby (and that I use for a lot of music related things) under the edge of the pickup ring so that the pickup ring is isolated from the top. That guitar now has a CC in it and, while you certainly can't play metal with it feedback wise, you can use high clean volume or light to medium gain and it is very controllable.
I don't care for PAFs in the bridge of anything. JB works just fine. It isn't a hot pickup in spite of what people claim (confusion about DCR and output will never go away will it..........), it is just hot enough to match a light wind PAF in the neck volume wise. In the neck of the first Cort I mentioned above, I have a Lollar Firebird neck, which is a 6k mini bucker using standard 42ga., so not exactly hot.
I also have a JB in the bridge of my Gibson CS-356, which isn't fully hollow, but sounds very similar to a fully hollow guitar. No issues at all with feedback.