Thanks for trying the game again.
I wasn't going to update the prototype again, but I had a sudden inspiration on how to mitigate the droids getting stuck in the warehouses, and I think this is now solved.
Build 0006 is now uploaded with the "stuck droids" fix, if you feel like giving it a go yet again.
The problem was that the Navigation system was sometimes sending a droid the "wrong way" through the warehouse as a way of avoiding droids coming the other way. If a droid was already moving in the correct direction through the warehouse, they would bump into each other and get stuck. I have simply placed an invisible object so as to make the inside of the warehouse less attractive (to the Navigation system) as an avoidance route. I tested it by using all 8 droids to build the same building at the same time, and none of them got stuck. There might be corner cases where they still get stuck, but this solution will do for the prototype.
As for droids colliding elsewhere, I am a hostage to the Godot devs. As they are all "agents" within the Nav system, they should not be bumping into each other like that. There is dev effort in this direction planned, so hopefully things should improve in future.
Thanks very much for the test/feedback offer. It will be a while before it happens, but I am very likely to take you up on that.
I also watched your uploaded stream of the game on YouTube. It was a very odd experience watching someone else play my game. But... it helped me understand your point about the menus and I have taken that on board for the future. I am not sure I will be able to do what you have suggested for everything, but I will give it a go where it makes sense. Creating this game is still very much a learning experience and it will be good to experiment with alternative ways of doing things.