(Note: It likely requires to be minified).
The important keys here:
This defines if it should be loaded at top priority or not. This is mostly to reorder the data structure internally. We've left it false for most of the Riot made ones.
Make sure this is true. This gives it priority over the Riot ones.
Just make sure "type" is NOT "riot"
Does "priority: true" mean that it will not load Riot ones at all, or that it will just appear above Riot ones in the list? If the latter, is it possible to disable the Riot ones?
This key may either be "any" or a single map id number (in string form). Some common ones you may wish to use:
"1" is Summoners Rift
"8" is Crystal Scar
"10" is Twisted Treeline