I like the idea but I worry about the space needed. Lets say you can load an image onto the signs instead of typing in letters. Now you have a variety of frames and with the modular signs you have a variety of sizes.
Now we get @Goblinounours creating his kitten hall of fame with 250 framed images of his amazing (I am sure) kitten. How much space does this take on the servers? Especially since, if he has a kitten museum then I have to create a puppy museum for my puppies. If this was all on local machines then I would be good, storage is the users issue, but for them to be stored on the Boundless servers I can see being an issue. I am more than willing to be shown/told where my space concerns are a non-issue.