I have to agree that holding down the E key may be irritating if required for longer periods but my intention(and this is just because of my love for snappy controls) was to make the upgrading as quick and smooth as possible. If you just want to upgrade a building quickly just press E-Left click and release E.
"But", I hear you ask , " why have a forge screen in the first place"
Two reasons:
First I intend there to be a way to click onto the turrets without upgrading them to see stats and potential upgrades without committing.
Second I wanted the map to still just feel like a "normal" map with "normal" props and only picking up the Hammer reveals the hidden possibilitys of turrets-from-anything. So basically it's yours for the Game feel and Fantasy, of which I value both highly in videogames.
And lastly I want to thank you for the feedback. I know it may look like I want to disprove your critique because I am the best and hurt by your inability to see the genius in my design.
But no that is of course idiotic. I really liked that you challenged my design and I have to agree that a Toggle for the Hammer would be better. Additionaly you got me thinking about my other more subconscious choices like the forge screen so I was forced to put my intention and reasons into words what helped me to take a new look at my design and the idea behind it.
So at last again=)
Thank you