Now ya see....I've run my tent with my lights at full blast from out of seedling into veg until now and have had zero issues with too much light. I say genetics will tell you how much light they like.
I guess "agonize" was the wrong word!

More just helicoptering over your plants. That's something a lot of newbs tend to do in the beginning. They'll be in and out of the tent 100 times during lights on looking for issues! Just let them do their thing and they'll tell you if they need anything. Of course, it doesn't hurt to be pro active but, again, just let them do their thing!
I try and be as inobtrusive as I can. I only open the tent to get a peek to see how they are doing and if there's anything obvious I need to attend to. After that they only get distrubed at feeding time and that's if I'm hand watering. Since I've set up my auto irrigate I don't even need to get in there other than to check for disease or pest infestation. Next run I'm going to set up a camera so that I can check on them without disturbing the environment.