I opened the print queue for my printer, and an icon for kde-print-queue was added to the dock. I pinned that icon and then closed kde-print-queue. If I now click on the kde-print-queue icon, it doesn't open because lattedock only remembers the executable name (kde-print-queue) and not the parameter that was used to launch it ("EPSON_WF_3640_Series"). In addition, lattedock does not give me any options to modify the launcher in lattedock, so I can't "add" the command line parameter. My only option is to manually create a .desktop file and drag that file to lattedock.
Actually, dragging a .desktop file to lattedock has its own problems. When I click on that icon, it does correctly launch the application. But then that application creates a second icon on lattedock.
Latte is using Plasma for its launchers, how do you solve this with Plasma taskmanagers?
I don't know how Plasma taskmanager works, but maybe Latte and/or Plasma could look up the process info when the process icon is being pinned, and then plasma/latte could just remember the parameters being passed.
Sorry this is not Latte responsibility, you need to find a way with plasma devs or you just edit the desktop file to include your parameters.