Of which version you're speaking of? I can't find any hint about, neither in current 2.0.1.2 nor in next 2.0.2.0 User Manuals. Obviously, I mean the RandomFlights=0-5 option in the INI file, like in Starshoy's DGen.
The current version, which is 2.0.1.2.
I still use IL-2 almost daily, both in building experimental missions and campaigns, as well as flying campaigns. Using both Starshoy's DGen and Asura's DGen Mod, Eastern Front missions spawn random flights on most missions with RandomFlights set to 5. Just because it's not in the manual doesn't mean it doesn't happen. Sometimes it's just a single recon, while other times there are up to two or three additional strike flights. Simple task to confirm in comparing the ops.dat line called for in the log file, and looking further down to see the additional random flights to be generated, if any. Alternatively, simply looking up the generated mission in the full mission builder gives immediate confirmation of the extra flights generated.
However, with RandomFlights set to 5, I have never seen random flights generated on any Pacific generated missions in Campaigns, and this has been the case for me since Pacific Fighters was first released. When checking the log file and mission builder, I've only ever seen the exact composition called for from the ops.dat mission line. Aircraft density settings don't count as it only alters the ops.dat mission line composition, and it's function is not to create random flights.
I can't speak for Western European scenarios, as I very rarely fly those. Use latest DT stock v4.12.
EDIT: I forgot to mention: If Aircraft Density is set high, that lowers the chance that random flights will be generated, even if it's set to 5. Likewise, if the ops.dat mission lines generate highly populated missions (i.e. 12B 12B 6F), then the chance of random flights being generated is significantly reduced, if not eliminated altogether. Random FLights seems to work best when ops.dat mission lines are of a relatively small aircraft composition, and Aircraft Density is set to Normal or Low, all of which leaves more room for random flights to be generated. As I understand it, currently Starshoy's and Asura's DGens allow only up to a maximum of 32 aircraft generated per side. The more that "budget" is filled, the less chance of random flights, even if there is still room to generate them. It would be interesting if Asura is working on doubling that number
, but I'm sure that depends on how well the "moving parts" inside the .exe will even allow that to ever happen...