I don't forsee any problems. I have done much the same, except with less meticulous planning.
I have one of those black plastic composters that municipalities out here like to give out. I find it useless for compost, as the pile never gets large
enough to heat up properly, but it's a great open-bottomed worm bin. When the ground is sodden, they can work their way up the compost column, which is at least half composed of spent wadded paper rabbit bedding, with the balance being
coffee grounds and kitchen scraps.
If the type of earthworm you're talking about is the one that goes up and down the soil column, where
Eisenia fetida stays to the upper strata and likes to eat compost byproducts, one added advantage is that the earthworm will be taking fertility and organic matter down the soil column with it, increasing drainage and improving soil structure far below where red wigglers like to range.
Let us know how it goes, though. No reason why it shouldn't work well. Keep us posted, and good luck.
-CK
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein