Overheated Silver Tip while experimenting
I was experimenting with keeping my brush warm while shaving and did overheat it two times. Not boiling but close enough to have the bristles leach some color.
The brush is still very soft when wet but when dry the tips feel a bit stiffer. So I would concur that overheating the silver tip is not a good idea.
Also, when wet the tips feel more rubbery. After the brush is washed they have the appearance of being coated in soap scum but this is not the case. It is just the texture of the tips has changed from being overheated.