Max is the literal max amount of slots you would like to allow for players to use. Reserved is the amount out of the max that you would like to remain as reserved. For example, if your max is 100, and your reserved is 25, 75 users without the bypass permission will be able to join.
Only placeholders for the kick message are specified in the config.
rslots.all -- Same as rslots.bypass.all
rslots.bypass.all -- gives access to all bypass nodes
rslots.bypass.reserved -- bypass the reserved slot limit
rslots.bypass.max -- bypass the max slot limit