No definitive answer from me
It sounds like you are pretty much spot on.
During the summer I practice on rocks at the same spot and distances, out to 1450 yds, that I set up on for the season.
Out to about 1K the first cold bore shot is a "kill shot" on the rock about 90% of the time. Higher when the wind is variable. The percentage falls off significantly at the 1450 mark as wind gets confusing on the back side of the hill.
The practice is well worth the effort and a great confidence builder.
Again I'd say you are headed in the right direction as evidenced by your choice to pass on that shot. It's not passing on that particular shot that will cause grief.