Thanks for, if nothing else, confirming I do not need to develop this integration for the US anymore. 
Honestly I won't completely rule it out, but it is reducing... I am open to a compelling case to invest in it, and am open to working with those willing to contribute... or, I am equally willing to help anyone willing to develop their own driver.
It looks like some developments have happened in the Home Assistant space with v3 of the API. Mitsubishi Kumo Cloud Integration - #523 by ventz - Feature Requests - Home Assistant Community
Based on that, I vibe coded a working Kumo app/driver combo that works for my US based mini split on my C8 hub. If there's interest I can make it available. It would be totally 'use at your own risk' as I don't pretend to be a developer.
@sburke781 - Have you thought about integrating with the Mistubishi Comfort platform at all? I was using your Driver back in the Kumo Cloud days and it was very helpful. Have not had any control of my Mitsubishi Heat Pump system within Hubitat since . 
I wish I could help but am not a software guy at all so would only be able to assist in de-bugging. Would be happy to do that!
I appreciate the offer to help @Levahj , but it is unlikely I will be looking at the Comfort platform. While the custom HA integration has moved to the point of supporting Comfort, my time / motivation for integrations more generally has waned in recent times. Nothing to do with the platform, people, etc, just life 
I’d be happy to help out in some small way if someone wants to take up the challenge, or even take my code and use it however they want, although I would suggest developing a Comfort only driver.
My suggestion would be, if you have the option, to look at the HA integration and see if you can get the control you need that way.
I will look into that. Thx for the info!
MELView authentication suddenly failing
Hi Simon,
I've been using the Unified Thermostat integration successfully with MELView in Australia for some time, controlling two Mitsubishi Electric City Multi ducted units.
It has recently stopped working, although I can still log into MELView normally using both the Mitsubishi app and web interface.
Hubitat is now reporting errors such as:
retrieveAuthCode_MELView: Unable to query MELView: java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1
followed by:
setAuthCode: New authentication code was NOT set
and subsequent MELView queries fail with a JSON parsing error.
With debug logging enabled, the authentication attempt appears to be receiving an empty/expired authentication cookie:
Cookie - auth=; domain=.melview.net; expires=Mon, 11-Oct-1999 11:00:00 GMT; path=/
The MELView username and password have been checked and are working normally in both the app and web interface.
As the integration had previously been operating without issue, I'm wondering whether Mitsubishi may recently have changed something in the MELView authentication process.
Could you please have a look when convenient? I suspect this may affect other Australian/NZ MELView users as well.
Happy to provide additional debug logs or test any changes if useful.
Thanks.
Thanks for the info. I will take a look when I get a chance, not sure when.