1.5 would probably be ok indoors. 4x gets a little blurry at less than all-the-way-across-the-house distances, but it's not too bad.
The non-illuminated reticle would be a problem in the dark, though. A weapon-mounted flashlight should solve that issue.
No idea if their custom shop will put a mil-dot in the 1.5-4x, but I don't see why they wouldn't.