It wasn't replacing coal, it was supplementing it for the increasing industrial and civilian demand for electricity.
Fair enough.
Does the Southwest Front withdraw or not?
I wasn't aware that there was any priority for supplies; all the Army Groups got sent what they needed, the bottleneck was the rail system to get it there. Since their logistics were on separate lines that were not in competition and divided by the Priypet Marshes there shouldn't be an issue with two separate thrusts other than having truck transport to bridge the rail gap to the army and the rail lines ability to get enough trains to the front. Rostov would be unreachable logistically. The Donets river would probably be the maximum line in 1941 possible logistically.
According to Creveld (I think you cited this recently as well), AGC had to surrender around 3,000 tons of GTR lift capacity in September to AGS to allow them to continue to advance; in order to get a Moscow thrust operation in late August/September, this couldn't occur and so that definitely won't be available for them (AGS). I'm also back to being doubtful about the ability of AGS to lop off the bulge again, having looked back over the relevant portions in
When Titans Clashed; Guderian managed to hit the Soviets in an exposed flank with an entire Panzer group in conjunction with Kleist advancing up from the South. Given you'd have a singular thrust here, I'm not as convinced of the possibility of success.