@tsaharms, tried 32100 and no luck, but one interesting change: with 32100, when I dial *228 instead of Sprint's "you are not authorized" I get METROPCS's OTA programming message!

Could it be that Cricket and MetroPCS have roaming agreements, and MetroPCS doesn't charge Cricket as much as Sprint does, therefore Cricket considers the MetroPCS areas to be "primary coverage" (dark green) instead of expensive "partner coverage"? This might explain a lot. Hopefully somebody with an inside line to Cricket can comment...