I does look like a quality line
But I still think that it sounds more like a III than a IV. 1000' is only like 330m. Say you did it with a 50m rope and it ended up being 9 pitches instead, I still think it would be a Grade III (sure, in the higher end of III) at that length and degree of sustainedness from the individual pitch ratings. But it sounds like it would be a good Alpine D+ for sure.
There was a similar discussion about the NCCS grades a couple of years ago that I have been to lazy to bump up instead of continuing the discussion here.
YDS = Class 3, 4, 5 etc. technicxal difficulty rating
NCCS (oops) = Grade I, II, III, IV, V etc. tme and overall rating.
Grade IV = a long all day climb possibly requiring a bivy on the first ascent.
3/16??? That's dental floss you cheapskate!
And I bet it isn't even stainless.
People placing junk like that keep the ASCA in business fixing their fuckups with decent anchors.
They leave them in Hotels so that when you are stuck with no reading material in some mediocre hotel, you will read the Word of God while sitting on the crapper. It has nothing to do with physical treatment of the book and everything to do with marketing.
You can't reel in on a short fall like that, it happens too quickly.
But Professor CBS will let you borrow his slide rule so you can start calculating fall factor while your leader is sketching so you can decide if it is worth it to reel.
Also your math only works for static ropes. More likely with rope stretch the leader will still fall 10 feet but on 13 feet of rope now for FF = 0.77