The plugin does what it needs to do in most instances.
However, there are a few instances where you might get some unexpected results. This can occur when you have multiple instances of the City Selector block active on 1 page with select2 activated.
Select2 is triggered by jQuery with some variables. These variables are defined in php and then passed on to the DOM.
The function which retrieves these values takes the first found option/field and uses those settings. We know this isn't ideal and we're working on a proper solution for it.