"But as a guest, wouldn't it be better to err on the side of more rather than less?"
Definitely, but all good things come of moderation, my good man. It's not a matter or more or less but if it's more it most certainly is a matter of how much more.
The great PVGC cut out tipping altogether because various guests were beginning to tip so heavily that Big Ed Byant once told Mr Brown (J.A. Brown) he was actually the cheapest, skinflint SOB of his acquantenance.
On the other hand, that wonderful lockerroom guy at Seminole who spoke to everyone the same way no matter who the hell they were or who they thought they were, was once asked by the Duke of Windsor (who apparently just loved the lockerroom guy) if it was OK if he tipped his caddie a buck.
The lookerroom guy said to the Duke of Windsor:
Duke, yooz is Royalty see, and since yooz really is Royalty there's no damn good reason at all that you need to be acting like some cheap sum of a bitch. "