Indeed, QRP RTTY is quite possible. I worked ER5LL (Moldova) back in October of 2012 via RTTY. And, it was on 40 meters, at night, using an indoor AlexLoop antenna, running 3 watts. True, it was during a contest, but nevertheless, a QSO is a QSO. Pretty cool! And, I was using -just- the KX3 in RTTY-D mode, sending via the paddles. 73 de Ray K2ULR KX3 #211