True, elevation should never be used as a defining feature, birds can and do move quite far out of their reported ranges on occasion (e.g. I saw Gould's Jewelfront >2000m and Andean Goose at 400m in Manu!!). Regardless, this bird doesn't have the warm, tawny tones I associate with Inca.
Leptopogon have some fun elevational boundaries. I did fieldwork on the Manu road back in 2014. We had ringing stations at Wayqechua, Cock-of-the-Rock and Pantiacolla. I spent less time at the upper elevations than others so I don't recall the capture data as well, but I'm not sure we ever caught Inca at CotR. At Pantiacolla we only caught Slaty-capped on the ridge >800m, below that I think it was almost entirely Sepia-capped.