@mattduguid, there was a recent thread where other people (including me) proposed something similar to what you suggest here.
This led to this statement from Let's Encrypt staff:
You can post your experience and opinions in the former thread, but following the latter thread, it seems like Let's Encrypt's current intentions are not to guarantee that staging and production will maintain a particular level of equivalence or parallelism with each other such that you can reliably condition a production issuance decision on a successful staging issuance.