(thinking too hard) .. a possible penalty for mining too late in the evening .. start mining at 1700, you sleep through the morning briefing and the crew randomly chooses what they feel like wearing and doing
Oh, I like the way you think - just, maybe let the "little grey cells" have a lie down for a bit! And a bun. Buns are good.
I agree with your thoughts on Void Field mining. (My first thought when that popped up was to look out for Void Cows. Ahem)
The passage of time is a Thing, and having a set finish time, regardless of when you start does feel a bit weird, as well as compressing the time available for one's evening rounds attending to the crew's needs, visiting the Space Bar (I note that there's no lock requiring an Any Key) and so on. You could say the same thing about T'Ris and her station walks. After the first one for each outfit it takes her all blinking day, rather than an hour, maybe two. What's she doing?
Have a set period, maybe a late start penalty as you said, and the rest is gravy. Or custard.
completely forgot about T'Ris station walks .. even as few as they were, it was annoying.
Late evening mining could even be a cumulative thing .. two evenings in a row, you sleep through the third morning, no briefing, not even knowledge of how your arcade bots did, or whether they were returned to you (random chance of missing morning delivery, delayed to next morning?)
Time management kinds of things .. consider timings carefully to minimize idle time, and maximize benefits against possible penalties, loses, or opportunities put off until later.
(Do I mine tonight, or go see T'Ris)