yes, speakers of agglutinating languages would be able to shove in a few more words, but a) they'd be looked at strangely by their compatriots for using some strange new combo word and no-one wants to have to decipher megawords like that b) (this should be obvious) switching to a different language means that the people who follow you can't read anything you say. So no, people will not switch to German, or any other agglutinating language to beat a word limit.