well, to clean an individual tile(or tiles) all you'd have to do is take it out, scrape it off and wash it. if it was parmenantly in your tank, you would have to take your dragon out of the cage as well as all the decorations to clean it. you would be confined to that small space so it might be difficult and awkward to clean. sealing the tiles into your tank would make the enclosure heavy, you would also have less fredom if you decide to change something.
in the end its up to you. most people(not all) here have loose-tiled tanks, im actually curious to see how it turns out for you :wink: .