That practice is not typically done in the NOVA fire departments from what I've seen. The APX models they mostly use displays it's assigned seating positions on each radio and is married to that seating position, therefore keeping UIDs consistent with each radio minimizing the need to change in CAD as often. The APX models Stafford uses doesn't display it's individual alias and therefore can't be assigned to seating positions the same way.
In our county, you routinely hear an officer talking with a dispatcher about radio assignments when apparatus get switched out / returning from maintenance. Usually, it's the mobile RID that is getting redesignated, but sometimes it's a portable. Other times, a reserve engine keeps its designation, but the portables are still tagged as being with the primary apparatus. So let's say reserve E304 is replacing E301, the CAD change is made that E304 is now dispatched as the primary engine from company 30 and its RID remains E304, but the portables still say "E301-2" etc. If the reserve unit comes from the pool, its CAD designation simply is changed to whatever unit it is replacing. Complications arise when a particular engine is uniquely capable in some respect, and has to be replaced....
Anyway, I thought the aliases were primarily for display on the radios to make it easier for the personnel to know what unit they were assigned to if a radio was found lying around the station, lol. AFAIK, just the SUID are transmitted by the radio on the cch / traffic subchannel. The CAD uses its own tags / aliases for SUIDs that are registered on the system.
