THe solution to the North American clubs wanting to play RL and promote the game in a new country is to help them get the game off the ground and if necessary, temporarily, increase SL to allow this to happen, with a long term view for the game to stand alone in a North American League or, something along those lines.
It should not be as a direct detriment to the "domestic" game.
So, why not ad one or two new clubs to SL, it doesn't seem that difficult but, there MUST be additional revenue, from either TV or other external sponsorship, to make it worthwhile for everyone, if not, we are burdening all SL clubs with additional cost and with nothing in return.
Of course there are significant logistical issues, especially at the end of the season with play offs etc.
However, IF RL could establish itself in Canada and/or the US, it could be huge for the game, huge and let's face it, RL could do with a boost.
The key is not to move forward with the "experiment" for free, there has to be some significant financial benefit to the game and not just crossed fingers.