I bought a round nose scraper from Packard and the instructions that came
with it advised sharpening it backwards/upside down. The results work fine
for me when taking those final light cuts.

I watched Eli Avisera sharpen his that way.

Right. It causes a burr to form, which does the scraping. The other way to make
a burr is to form one using a burnisher. Scrapers remove wood by... scraping,
not cutting.