I'd guess, if as you mentioned that tree it's on needs to come down, and it's not very huge in girth , you could remove the entire thing by cutting the trunk just above and below the area where the staghorn is attached and leaving the entire plant intact , and still attached to the "log" you'd get. Might take some finesse to cut the tree without damaging the fern however. I would guess as well, the roots don't extend into the "trunk" itself but are only attached to the outer bark of the tree and that might be removed possibly?? Not that familiar with mango tree bark however, and it might be more difficult than I'd expect.

Resurrecting this discussion! This is my staghorn, he’s mounted on a salvaged board my aunt made just for him lol. The board is about 13x13 and it hangs next to the east facing window in my bedroom. It gets morning sun for about 2 hours, then indirect light all day. He has a few ratty fronds from when I bought him and from the mounting process, but he seems to like where he’s at. He’s put out a new antler frond and is working on a shield frond at the moment

Very, VERY easy fern to grow, probably one of my favorite ferns. Yours may be being kept too moist. Use a very freely draining mix. I mix a lot of orchid bark into the mix. You can grow them in hanging baskets just fine..., just let them dry out some but also don't forget to water them. MIne go outside in the growing season from late March till November hanging in a grove of Eastern Hemlocks.

how about a pic .. did you buy a perfectly happy plant.. and bring it home and immediately repot it because you werent sure of the media?? your fact scenario is a bit lacking.. fill us in with what went on ..... did you moisten the new media first ... and dont forget a pic... ken