In a couple recent Forgotten Weapons episodes involving modern, compact stocked pistols  (Universal Service Weapon or USW), Ian noted that his red dot sight had a large parallax error that dramatically reduced accuracy.   Although this would not be a big deal if the weapon were held at arms length, he was holding it close to his face.  Since consistent cheek weld appears to be an issue, that might be addressed as well.

I am not very familiar with the various sighting systems, so which ones would work well in this situation?  Note that part of the purpose of these weapons is ease-of-carry, preferably as close as possible to a typical service pistol.

Thanks

Maybe something like an EOTech sight?

The original USW that began the concept had a custom sight made for it, the Aimpoint Nano:

https://www.recoilweb.com/images-of-new-aimpoint-nano-mrds-leaked-102317.html

So I imagine the Nano, or the successor to that optic, the ACRO, would be a good starting point. 

My holosuns haven't done bad with it other than there's a bit of a blurring issue with my ha403 circle dot if it's too close or a little too far away from my face.

With my pa md25 or my other pa basic micro dot I don't experience this.

The biggest thing I've noticed is that mount height sensitivity is kind of a thing

Here's a selection of some of my known good dots... Sorry about the medical stuff clutter, I had a pretty serious surgery recently and I'm still doing dressing changes etc.