West 207 is a non-blush hardener. I have no doubt that WEST did their homework and have a good formulation that avoids a lot of trouble. The fact that it seems to hold together is not a good test. As Nick said, sometimes the effect of incomplete bonding doesn't show up at first. And nobody knows if your adhesion is at 100% of the possible strength or 50%. You should pass this by WEST and see what they say. And, I'm sure they recommend good practices well within the safety limitations of the product rather than state the extreme limits of time between coats that could be used?

I was once doing a repair and as I sanded the surface, the glass was flaking off in small flakes. This is the classic case of an incomplete bond. As epoxy ages it gets more brittle and that's when these problems can arise.

Glad to hear the 207 seems the do well but I would still build using the intended time WEST says for a chemical bond or whatever prep they recommend between coats.