Update Script
Suggestion
Whenever an app you have installed is refreshed, the app gets uninstalled and reinstalled. For some apps, this may take too much time, so they could supply an update Script that will be executed instead of uninstall then install, but if not available, use the current approach.
Let's talk specific apps please. Is there a specific app you have in mind that could be updated much faster if it was not first uninstalled and then installed?
Pi-Apps already avoids autoremoving dependency packages during an update, reducing downloading bandwidth and allowing those dependencies to remain installed during updates.
https://github.com/Botspot/pi-apps/blob/407eb62b89c12bd1c12eee7bec2c2ee125ed41a4/api#L765-L776
Closing due to OP's inability to respond