It is awkward to use sights, to use a sight it needs to be 'open' like a red dot and you adjust your perception of the view, or you need a riser or angled rail to move the sight to be more accessible
Strictly speaking you should be able to see where you can shoot, so the sight becomes an added extra
Any zoom affects your perception and situational awareness between using the sight and using your eyes
However - with first strike and sights they can help, but to make any use you need an adjustable riser and a crossbow sight rather than a gun sight. Once you have those you then need to shoot a lot of first strikes for practice and to get used to the sight and how paintballs & first strikes fly
It's getting a little popular to accompany a camera with a sight for filming, you could use this to view the screen but now have a low resolution view of a zoomed image