Creating custom mobile emulators for layout
My client's media queries are based on the standard bootstrap media query sizes (576, 768, 992, 1200) and none of the existing emulators hit these marks exactly. So I created new ones based on /libs/wcm/mobile/components/emulators/ios/iphonex. I copied it and modified its cq:emulatorConfig properties, setting the device-pixel-ratio to 1 and the width and height to the approprtiate values.
After this I updated the emulator list in /etc/mobile/groups/responsive/jcr:content and it works.
The problem is that I've modified things under libs to get this to work. I've tried moving my custom emulators under a /conf directory, and pointing /etc/mobile/groups/responsive/jcr:content at this. This breaks the layout editor - the page refuses to load until I remove the custom emulators from the list.
Has anyone successfully done this without modifying /libs?

