What's stopping you from assuming that players would want as much info as possible and rolling insight as background rolls constantly and include the resulting insight in the update in the way that would feet the narrative?
What's to say I haven't been? I can confirm I've rolled two so far. They went well.
Asking to roll the check might glean more than Vilina's passive insight on a subject, or might provide specific information to the players that they
know, unequivocally is the result of attempting such a check. That can provide confidence or peace of mind, confirming that the attempt was made, even if its success is still in question.
That all being said, I'm willing to try out the on-demand insight checks, though my work schedule might complicate those as I can't always be at my phone at all times. Further, making such a check takes some time and consideration. If someone tries to lie to you, the check I roll then is your initial gut reaction to the lie. Any active attempt that follows requires a few moments of thought. So asking for such a thing to occur on-demand outside the regular updates might end up being impossible if we're within the split-second activity of a fight or emergency situation, or your delay may cause the NPC(s) to react before you can act on the results of your check.
Now, in this particular situation neither of those are issues; Kid Omega is patient and you don't have anywhere to be anytime soon. You take a few moments to piece together what you've discovered about him since you met, and while there's
something about him that overall makes you uneasy, in this particular instance he seems to mean no harm. There's an almost puppy-dog like level of excitement to his posture, and there's a lot of earnestness to his inflection.