I'd like to suggest adding a filter for a crew's (or assigned crew's) specific training. the main use of this would be for critical care staff, where you can just have a critical care ARR button and it sends the nearest unit with a CC trained crew member onboard/assigned to it.
I know you can assign your own custom vehicle categories for a similar effect but I'd prefer an ambulance, RRV, GP etc. to not all be grouped into the one catogory.
This could come in useful in the future as well if more types of training are added - since not all CC staff may be trained with all other types of training (if you get what I mean).
I'd be interested to see your opinions in this idea,