Wow, amazing...done and done. Many thanks, Mike!
I'll likely make further tweaks to the dimming response, but my app/driver are fully functional now - probably time to post the code.
I found @bobbyD's thread Custom Device Drivers [Wiki], which led me to @csteele's thread Inventory of User Device Drivers? - #8 by csteele, which took me to HubitatCommunity · GitHub. I see in GitHub - HubitatCommunity/HubitatPublic that:
...you need to be a Member first. Therefore, to add a repository, contact csteele-PD (c steele) · GitHub. Repositories can be anything from a Readme pointing to your personal site to a multi-contributor, versioned driver or app! For more information, check out the forums at: https://community.hubitat.com/
I'll drop a direct message to @csteele straight away...
