I can mount almost any guitar in the neck jig to straighten warps or twists from years of heat and tension. After setting up the jig, I use a fretboard heat blanket to soften the glue under the fretboard...
Centering under the lowest point of a warp with a threaded neck brace, I can level the neck to its original position with the truss rod loosened. After heating the fretboard with the heat blanket, when the glue hardens, the neck remains straight...
I can raise or lower up to three points under the neck for difficult to manage warps. This helps even out the tension on the neck for better support...
As you can see, bolt on necks are a little easier to mount and straighten...