I was trying to figure out how to use one of the pre-made templates in developer mode. It looked like the only way to set a template was to switch out of developer mode. I thought maybe I needed to switch out of developer mode, pick a template, and then switch back.
I assumed that the presence of a toggle switch meant I could simply toggle back into developer mode whenever I wanted to. Now I'm stuck in non-developer mode, where I have access to the pre-made templates… but can barely do anything with them.