Not sure if this is quite what you mean, but kind of sounds like a feature I could use too. My workaround was to create a couple of extra users so it's easier to find those visits in the schedule.
One is named "unconfirmed appointment" the other is "cancelation list". In the team settings, I have their colours listed last, so they will always show up on the calendar if they are assigned to a visit.
The first, I use as a placeholder so I can quickly see it's an easy visit to shuffle around. Once the visit is confirmed, I remove that user from the visit.
The other one sometimes has an appointment, but often sits in my unscheduled visits. When I need a filler, I can check there for jobs that show up in the right colour.