RASAero II has been used to generate aero data for launch vehicles run on other ascent to orbit flight simulation programs. In fact the last update of RASAero II (Version 1.0.1.0) included changes to improve models specifically for launch vehicles.
From the RASAero web site for the RASAero II Version 1.0.1.0 update:
https://www.rasaero.com/dl_software_ii.htm
"Added extension to power-on base drag model for very large nozzle exit diameters at supersonic and hypersonic Mach numbers, with the nozzle exit area filling a large portion of the rocket base area, for more accurate power-on drag coefficient (CD) predictions for first and second stages of satellite launch vehicles."
Chuck Rogers
Rogers Aeroscience