I simply looking to disable the GPU in Indesign and other Adobe applications to preserve battery life while traveling with my laptop. I thought this should be a very easy thing to do by disabling the "GPU Performance" in preferences but this simply does not seem to be the case. By doing so the application still seems to use the GPU of my MacBook Pro. I'm able to do this with applications like Affinity Photo without issue, but I'd like to continue using Adobe products while on the go. Without Adobe products running (and GPU Performance turned off) battery life is about 7(ish) hours. However, with just one Adobe product open (and idle- in the background) I'm run down to maybe 2 hours maximum. So I'm forced to close the application even thought I may need just reference information in one of its files. This gets tired very quickly.
I do not have a the same problems with the vast majority of applications I use as I do with Adobe products.
I have a 2015 MacBook Pro. I use it almost all day. Even when using the GPU feature in InDesign, Illustrator and Photoshop (all which use the GPU), my battery show very decent performance, even though I use the computer for many hours a day.
I use a utility called Fruit Juice which tracks my battery usage and encourages me to use good battery practices. Here's my last week of battery use:
I don't have an answer to your problem but I don't think it's a common one. Maybe someone will have a suggestion.