Sure Krusty.
There is a max take off weight. If the a/c is carrying a full load of bombs and carrying a full load of fuel that would put it over its max take off weight.
There was a reason the chart Ack-Ack posted were produced, for all a/c.
and it from the looks of that B29 chart, the MTOW was 140,000 lbs.
ferry range fuel = 54900 lbs = which I assume would be 100% fuel
the "max bombs" fuel = 38690 lbs = ~70.5% fuel
I presume hitech will have 100% in the hangar equal the 70.5% if you take all the bombs. either that or he could make it interesting and let people take the full 54900 with 20000 of bombs and be over mtow, and try some logging/brush clearing off the departure end.