I am a new player, and I can’t help but wonder about how troops and buildings that I haven’t unlocked work. I suggest making a “testing lab” where players get a fresh plate like the one you get at the start of the game. Players can then open a menu allowing them to place a town hall or anything they want from the COC shop, even if they haven’t unlocked it. Buildings would be instantly placed with no timers or upgrade timers, and players can upgrade buildings with a slider instead of clicking. This would allow players to create their own scenarios and test buildings and troops that they haven’t unlocked. They could also place a CC and set troops for it, just to add a bit more Defense. This would be like a “creative mode” and you would be able to name and share the labs that you have created. Then others can test them out with certain troops designated by the creator. It would just add a little bit more creativity to COC.
This is just an unrestricted version of friendly challenges. This kind of idea would require the 24 hour friendly challenge cooldown to work, otherwise you could recreate an enemy clan's war base and sandbox it repeatedly for easy war wins.