I'm not a fan of shaving a bridge.
I used to be a purist and say "why bother? myself, but I saw several guitars here whose owners simply couldn't justify the cost of a reset, on guitars that wer so old tht it was possibl they'd reached a final point of stability where they were at, and in some cases had bridges so massive that taking a little off the top might have actually
helped(!)
So now I can see a justification for it but only in certain circumstances.
It just ruins it for when the proper neck reset fix is done. I was lucky to get a NOS bridge from Hans Moust when I had my D 35 done. I think the fear of Guild neck sets is the large flat heel needs more steam, which can cause finish issues.
(Br I know you know this, but):
The neck joint's finished over and needs to be cut through no matter what.
Any Guild reset's going to need finish touchup to be truly "correct".
The large flat heel issue was more about surface area to be loosened up, and yes longer steam exposure can be required.
But recently our member Chris Cozad who's done his own fair share of great work explained something I hadn't recalled hearing before:
Because there was so much hand shaping involved in Guild's dovetails, it can be hard just to find the pocket with the steam needle. He showed an example of a guitar that need at least 2 attempts before he could finally start getting steam into the pocket.
Another issue that reared its ugly head was that if that nice flat heel we love is too thin, it can be damaged beyond recovery on removal or simply be too shallow to be able to be re-angled.
