Reporting in ...
02 LC. Watched the provided video and started connecting things up. There is an alternate wiring harness which I didn't use [didn't fit].
I swapped the HVAC 'black box' as seen in videos from the truck to the new head unit. Pretty straight forward and connected it into the provided loom.
Once plugged in, HVAC works. Front, back, AC, etc. Connected to phone bluetooth with no problem - can see song playing from phone and affect it with the interface. Turning on the radio causes the antenna to go up/down.
No sound though. I happen to have see an overland shop in TX that bypassed the stock amp - how do I wire into the stock setup? Tried all available combos to see if something came to life ... no dice.
Will reach out to their support now and hope for a quick response overnight. Fingers crossed!