Medical user: I've been arguing that for more years than I care to remember ! Having grown for years outdoors in a small suburban garden before moving house I can tell you that these plants will aclimatise to whatever level of 'darkness' they get used to, in spite of outdoor garden lights and kitchen lights etc going on and off I never had a single hermie plant outdoors. Hermies are much more to do with genetics than the lack of total darkness at 'night'. Now I know that some will jump on me for this BUT its based on MANY years of growing indoors and out. When I read of growers sitting inside a grow box to check light leaks it makes me laugh
Use common sense and think in terms of 'nature', work with good stable genetics, and just make sure they are not subject to sudden bursts of artificial intense light...... you will be fine. Like you say moonlight is amazingly bright (full moon!) yet of course it does not cause any harm to outdoor plants, of course it doesnt.
Stable genetics are the key, that and common sense