I ALWAYS leave at least an hour to setup, sometimes longer depending on the venue. A large mansion room with challenging stairs will take longer than a marquee in the garden next to the driveway!
It’s all common sense really, and I’ll ensure I’m fully setup and ready to go before the start. If you need me to setup the day before, or the morning before an event in the evening, then I simply factor that into your quote. Anything goes.