Found another one. Creating and using blueprints works fine, but using the vanilla "select new content" blueprint feature leads to a non-recoverable error when the selection includes a dispatcher. In this case it seems to happen no matter what the dispatcher is set to.
Error while running event RailLogisticsDispatcher::on_player_setup_blueprint (ID 70)
Index out of bounds: 32 > 0.
stack traceback:
[C]: in function 'set_blueprint_entity_tag'
RailLogisticsDispatcher/control.lua:233: in function 'dataToBlueprint'
RailLogisticsDispatcher/control.lua:247: in function <RailLogisticsDispatcher/control.lua:243>