Okay, so I've been wanting to remove the party command window from my project. Yanfly's Battle Engine Core has the ability to skip it, but some of us want it removed outright. I've tried finding plug-ins to no avail.
As I've discovered, thankfully, you don't need a plug-in. All you need to do is comment out two lines in rpg_scenes. The lines are:
2183: this.addWindow(this._partyCommandWindow);
^ Commenting this out removes the party command window. However, you can still cancel out of the actor command window, and since there is no more party command window, you'll be stuck unable to do anything. This leads us to the second line:
2192: this._actorCommandWindow.setHandler('cancel', this.selectPreviousCommand.bind(this));
^ Commenting this out will keep you in the actor command window, unable to go back.
I've tested it, and found no problems from these two simple changes. So if you are looking to remove the party command window, this is how you do it. Bear in mind you'll need to come up with a different way for your actors to escape from battle, since this removes the default option.