Sparing the rod...

Here's a compelling case that reinforces my reasons for not using a truss rod that adjusts through the soundhole on my own guitars. This is a Washburn Festival Series acoustic/electric/ hybrid.  It's not a high-end instrument but it's in excellent shape and it does what the owner wants it to do.  Unfortunately an attempt has been made to correct a rising action by tweaking the rod.  This guitar has a double-action rod.  It seems to have been twisted the wrong way. The action was cranked up close to a full 1/4" before the nut snapped!

The only way to correct this is to remove the fingerboard and install a new rod. It might need a neck re-set  but that's impossible to evaluate in its present condition. I tend to think not. The board is bound in black plastic that might turn to goo when I apply heat. The fretboard is thin. I'll bet the frets are glued in, too.
The repair cost would come perilously close to the retail value of the instrument.  Now. If the rod had been installed the other way - adjustable at the head, then there's a good chance I could have drilled it, hooked it with some pliers and pulled it out. At the very least I would have been able to release some of the tension hopefully making it playable.
Preserving strength around the headstock is a thoughtful design feature, but in this case it has made repair economically unfeasible.