I start my own build of pidgin with a batch file.
start ./Pidgin/pidgin.exe -c Data /nosplash /minimized
Frist feature is to write PIDGIN_MULTI_INST to windows variables. This could be done to start the launcher with an option -PIDGIN_MULTI_INST=2.
Second feature to be able to add /nosplash and /minimized to the launcher so no splash screen will pop up and pidgin will be started into tray and not fullscreen.
Just grab the INI file and adjust it. An example is in PidginPortable\Other\PidginPortableSource. Copy it to your PidginPortable directory and change it so it reads:
Sometimes, the impossible can become possible, if you're awesome!