Zygote is a terrific starting point for field-provisioning and SSID and password but assumes you only need to do so when your existing credentials are invalid. To support pre-loading credentials setup.toit must be able to start an AP even when Jaguar or Artemis has wi-fi running. Jaguar can get around this with -D jag.wifi=false but how can I turn off Artemis' wifi temporarily? Temporary turn-off of Artemis' wifi would also be beneficial for when I need to run a sensor for an hour but don't need wifi or it's current draw in the meantime. Thank you.

The https://pkg.toit.io/package/github.com%2Ftoitware%2Ftoit-artemis package has (most) of the functions you need. You can run with

run --offline

to force Artemis offline, but you can also ask it to synchronize because you are going online anyway.

This is great stuff. Thank you.