There’s really no disadvantage to shutting it down nightly, apart from the warm up period in the morning. The lamps and ink will need to come up to temp before you print. A couple extra quick purges to rebuild the meniscus in the jets perhaps, but that’s about it.
shutting it down completely honestly isn’t a bad idea in this day of uncertainty, if you do your nightly 8 hour maintenance and shut it down, and the power goes out over night, you’re in a better position than if it was in sleep mode.
ink in the jets and lines will be fine, it’s UV, so it isn’t going to cure in a day or three. Additionally, if for some reason the compressor quits during the night you don’t have to struggle with the no main air system error.
personally, I prefer to put them to sleep as in the morning, quick maintenance and you’re off to the races printing, but apart from that 29-30 minutes getting started little benefit.