Is it possible to set Folder Numeric Prefix to be enabled for new pages in the admin panel by default? I don’t see an option in the configuration settings but I thought I read somewhere it was possible to set in one of the yaml files(?) 
There’s not an option, but Grav actually looks at the siblings of thew new page, if the are mostly ‘visible’ ie, they have numeric prefix, the new page will be created with numeric prefix also.
hmm I’m not seeing this happen, is it because my pages are modular?
Maybe create an issue so i remember to look at it: https://github.com/getgrav/grav-plugin-admin/issues