The VHB tape is too sticky. You need to be able to glue-on the magnet, test it and reposition it, if necessary...
Its actually easier to remove than hot-glue. You can peel it off with your nails and done correctly, won't leave any residue.
In any case, you don't glue/tape it direct when you're testing the position. Its a whole lot more manageable just to use some 'Blue-tack' to test the position first, note the position then tape/glue it on for the long term.