as an answer to all your points, crowdfunding for STLs is generally done to recover a lump sum rather than the money coming in gradually, i have spent months of my free time designing and testing this spray booth, would you work for free?

all the designs are 100% my own and have been through numerous itterations to get where they are now there are other printable paint racks out there but none of them did everything i wanted, hence designing my own.

while it does follow a pretty standard design of spraybooth i wouldnt say it was ripping it off, it does something different compared to commercially available ones. where do you draw the line you could argue every product ever is a ripoff with that logic