I've already sliced all my foamcore into 6" tiles (and 6"x3", and 3"...) so I'm kind of pot-committed to that format for my tiles. I want to have a go at using the EZ-Lock system for building stuff, so I want to carve holes in the tiles like Fat Dragon intended. But, I'm still planning on using a TLX-esque tab system for hooking the tiles to each other. Last night's quick test seemed promising. I need to make the EZ-Lock columns though.
At the same time, I'm realizing that I should be able to put TLX anchors on the tiles, allowing me to use the tiles for TLX purposes if I wanted. Moreover, I should be able to do my little retro-fit inside the 1/2" Fat Dragon posts so they grip onto the TLX anchors nicely. I'm still convinced I can get the best of both worlds.
I hope tonight/tomorrow to get maybe four tiles made up so I can link some walls together on something and finally snap a photo.