The different emphasis comes down to your comment that:

...they support SI despite not agreeing with SI's specific arguments. Perhaps you should, too...

In my opinion, I can more effectively support those activities that I think are effective by not supporting SI. Waiting until the Center for Applied Rationality gets its tax-exempt status in place allows me to both target my donations and directly signal where I think SI has been most effective up to this point.

If they end up having short-term cashflow issues prior to that split, my first response would be to register for the next Singularity Summit a bit early since that's another piece that I wish to directly support.