Oops - I was out on leave, just seeing this now. Filed a GitHub issue to support/document such a use case: https://github.com/intersystems/isc-codetidy/issues/66

Currently, the expectation is that isc.codetidy is configured as a server-side extension so it automatically applies on e.g. isfs-mode editing from VSCode, or any use of Studio (if you still must). I *think* the edits will also work for client-side editing and be reflected automatically, similar to storage definition changes, but that isn't part of the workflow it's intended for.

FWIW, this is my favorite set of guidelines of the sort I've read so far. I particularly appreciate that you don't throw out postconditionals entirely (and agree on the appropriate uses you've described).

@Ashok Kumar T thank you for raising these issues - we'll make the error message cleaner and explicitly point to flexible python runtime configuration as the likely culprit.