I suspose he is assuming the appropriate engines are available.

Unless the Luftwaffe changes its doctrine they will be using this plane as a tactical bomber, like the He177 was abused.

Assuming the doctrine is changed. Maybe Wever is not killed in a accident, then enough of them have to built to make a difference? How many He111, Ju88, or FW 190 are not produced so the HO229 are built?

The US & Britian had to build thousands of heavy bombers of this class in order to make a noticeable dent in German & Japanese warmaking ability. Is there any concieveable way the German aircraft industry can put even one or two thousand of these aloft?

One huge advantage the US & British antiaircraft defenses had from 1941 was the proximity fuze. These proved devastating vs agile Japanese tactical bombers. I'd expect the less manuverable heavy bomber would be easy meat for the radar fuzed AA ammo of the Allies. Losses of the HO229 would rival that of the Allied heavy bombers.