Also I don't think I mentioned because a good number of you are participating in the March HAL too, but I'm lurking here because I am doing an unexpected staggered hatch. For those who aren't on that thread, I had a variety of eggs come (mostly BBSCM, partridge orps, olive eggers, and some local CCL crosses), but while absolutely everything else developed, the BBSCMs were all infertile, so the breeder sent replacements (and also more blue/green eggs). They're 13 days behind the initial batch, which are due to hatch on Friday.
I've done staggered hatches before, but it was of the "I have more eggs than I can fit in my incubator, so I'll just put these in as clears get pulled out" variety. That's actually gone surprisingly well for me. My craziest result was a shipped egg that hatched out 2+ weeks after its peers that went in first. On brand, she's an "olive egger" that lays brown eggs, when she darn well pleases.