Is there a way to use the schedule mode and set away in the night and geofencing in the day? If not, that would be really great to implement!
Not natively. eufy support describes geofencing and schedules as separate mode systems, with geofencing automatically switching Home/Away based on phone location and schedules used to switch modes by time.
So the request geofencing by day, away at night — is generally not built in as one combined rule. The usual workaround is a custom mode plus a schedule, or a separate automation platform like Home Assistant.