Ad-hoc customers don't seem to get the 300min of free parking and immediately pay 1CHF per 15min. Swisscharge users have 300min before the same price applies.
I notice this location has opening hours in the Swisscharge app. Shows 0-24h Monday through Friday. Closed on weekends. The times seem pretty arbitrary. Presumably it's not a gate that an employee must close manually, or it would be aligned with business hours on Friday and Monday.