Is there any benefit to feeding a Pokemon 10 golden razz berries?

Solution 1:

A Golden Razzberry functions slightly different than the regular Razzberry. When using this berry, it fully restores the Pokémon's motivation in the gym. In a casual manner, feeding a Pokémon multiple Golden Razzberrys would be a waste.

However, contrary to my previous comment, a benefit to using multiple Golden Razzberries within a short period of time would be to defend a friendly gym. If you are close by, or have a defender yourself while at a distance, you could monitor the motivation levels and feed a Golden Razzberry when a Pokémon is about to be kicked out. Rinse, wash, repeat until the attacking team has given up.