Considering that there is no limit to the max resolution of screenshots, I don't see how there could be a cap on the max resolution either, since the client re-renders the window when doing higher res screenshots than current settings.
"It's shite being tryker! We're the lowest of the low. The scum of Atys! The most wretched, miserable, servile, pathetic trash that was ever shat into civilization. Some people hate the Matis. I don't. They're just wankers. We, on the other hand, are COLONIZED by wankers. Can't even find a decent culture to be colonized BY. We're ruled by effete arseholes. It's a shite state of affairs to be in, Marceline, and ALL the fresh air in the world won't make any ****** difference"