This question arose on the Twitts and the person wanted to know if waiting for the first renewal was a good idea.
In short, no.
First off, the days of counting on the NIH renewal application being funded, even given great productivity, are over. Tactically you need to shoot for overlapping awards just to ensure continuity of a one-R01 sized lab.
Second, it is my continued view that it is really hard to make it as a single grant lab in the long term. You need diversity of projects because one might run into doldrums now and again for reasons outside of your control.
The third point addresses a followup concern- can newb profs handle the load of two major projects? I say yes. I can't think of a single scientist who struggled and/or failed because they had two R01 support in the early years. I'm sure they exist but I can't think of any examples from my experiences. I do know a few folks lucky to get two major awards early (first 2-3 years) and they did (and are doing) just fine.
OTOH I can think of several examples of folks who struggled with just one award and for whom I think things would have been vastly better with two grants.