@Vradcliffe,
Thanks again for your involvement in this. Your patience and dedication to see this to fruition is greatly appreciated.
Foe those looking into this, the harness can be purchased here.
https://harnessdr.com/product/2019-2021-silverado-sierra-steering-wheel-lin-bus-harness/
A few things to note:
A new compatible cluster swap is needed. The new cluster needs to be custom programmed by WAMS - 2019+ (T1) Denali / High Country Cluster Upgrade Kit - White Automotive & Media Services - @GTPprix is the only company I use for this type of work.
Since a new cluster is needed, might as well upgrade to the nicer Denali or High Country Cluster.
A few customers have also reported that they gained radio controls (IOR) radios and have restored backlight illumination on the left side.
Keep in mind, that this is still a fairly new retrofit and release - so individual results may vary.
Thanks!