Yes, i think all versions (mine and other) have bombrack as default, that reflect the historical reality.....
For engines...
First batches of D9 were fitted with the 1750 hp version that was the "basic" engine from september/october 1944.. Then, they were fitted with a semi auto additionnal extra boost that gave 1900 hp for take off . This boost was manualy engaged on ground and under something like 2300 m (don't remember the exact altitude, and i may be little bit wrong) and automaticaly beyond this alt in order to spare fuel.
All D9 were retroffited with this extra boost by the end of november or beginning of december, most on field. After that, during december, mw50 began to be fitted and was serialized in very early of 1945. So, here is the explanation of the 3 versions. In fact, early dora with 1750 hp is usable only for october/november 1944 only.