Again, discounting his mixed results, he lost a total of 3 sets in 4.5 play during the 2019 season. One of those sets was to an eventual 5.0 bump, however we won the match (and also won more total games). The other 2 sets lost were in doubles, and one of his opponents in that match was an eventual 5.0 bump.Maybe some of his best wins were against other self-rates who had yet to garner a rating? Maybe he was in appeal range? Did he have any close matches against 4.0s? That's the best I got. Sounds pretty ridiculous otherwise.
Really, I have no idea how he's still at 4.5. I don't believe he gamed the system, because if you look at his results, most of his matches he barely lost enough games to lose a set combined.