Something I thought of that would be cool, but not a good use of money.
Lego-sized BLB, no raised studs, and the top and bottoms would have rod magnets inside the brick. The rod shape forces the magnet of another brick to stay on one stud. This could be an interesting merchandise.
I'd also want the B on the left breast, with the default avatar on the back.
And how about a shirt that I have that says "Friends don't let friends go to Virginia tech" and it has a UVA symbol on the left breast. This could be modified to fit Blockland and Roblox "Friends don't let friends play Roblox"
What about a default head decal on default head color on a keychain?