After learning STNE using ktouch, I found adding R and I at the same time hard, so I made a new level to stick in between original levels one and two.

Edit /usr/share/kde4/apps/ktouch/colemak.ktouch.xml and insert:

  <Level>
   <NewCharacters>i</NewCharacters>
   <Line>it tit init einstein nineteen in insist insentient tiniest</Line>
   <Line>site tie tin intense is its sentient sin tininess entities in</Line>
   <Line>int sins tennis in sit einstein stint snit intent nit tint</Line>
   <Line>it is insentient intense insist nine is tiniest nineteen tint</Line>
  </Level>

where appropriate (and remove 'i' from the NewCharacters tag of the original level 2).

Some words appear more than once, just like in the other levels.