YEah I would say it's not recommended at all but practicing on scrap is always a good idea even just using heat.
But it begs the question... This is a hand made guitar? What exactly is wrong with it? Why do you want to refinish it? Why remove the bridge? Why not send it back to the builder if it's broken?
FWIW I use a heat bulp in a lamp as a heat source. One of those lamps on flexible arms that you can move around. Get some thick box cardboard and make a cut out the shape of your bridge, then line the cardboard with foil and place it around the bridge so only the bridge is showing. Put the lamp about 8in away and leave it on till the wood starts smoking (barely) then ease in a very very thin knife. Back to the lamp, knife, lamp, knife and so on till it's off. You have to be real careful about runout on the top and poking the knife under the spruce fibers. Don't ever force it. Period. Just don't do it
