More often, closer to 200m (219yd). This will vary due to barrel length, twist rate, ammo used, height of the sight over the bore. That’s a huge part of why folks are heavily encouraged to confirm desired zero at true desired zero distance, if one has a venue capable of doing so. Many do not, and have no choice but to do a grouping exercise at a closer range and call it as good as can possibly be achieved.
For example, mine zeroed @50yd, are smack-dab POA/POI @205m. I left them there, and have shot them so that I know where I’ll print at other distances.
Anyway, yes, you’ve essentially got the gist of that zero type and how it performs; WAY more to be found for that and other zeros, and the holds one should be prepared for, in the following thread: https://www.m4carbine.net/showthread.php?t=65679
At ranges inside 50yd, you’ll want to hold high for small/low-percentage targets. +/- 2" @ yd, ±/1" @25yd, etc. You’ll see that on the charts in the cited sticky thread…
What device did you borrow? Is it a triangle, or a chevron? They’re not the same; a chevron is not filled-in for a reason.
Reason I ask: With a Trijicon ACOG variant with a chevron reticle, one can still effectively mimic 1x RDS capability using a 50/200 zero, with the understanding that it’ll likely somewhat invalidate the BDC (which may be the case anyway, since those are “recipe” optics where the BDC depends upon a specific mounting, barrel length/type, and ammo).
If it’s a triangle reticle, or some other brand with a chevron…suffice to say that more info would be worthwhile, if it’s available.