If you want it perm then use epoxy. I used silicone and that's what most use. Unless it's got a threaded center, I would assume even silicone is permenent. There was like zero clearance with tungsten and they wouldn't even fit in the 2 nearest holes. No idea how one would get them out.
I actually used hot glue works good so far. It should be easy to remove if you want to especially since I threaded the weights. I did diy job with 5/8 brass hex rod and a hacksaw.
i used a marine epoxy. Was flexible and super solid. Tried a couple different other glues and they would come loose after a match. The marine epoxy is permanent