Yes, do what Geohec said. You lost them at SQBR6. They have no clue what that is.
They should - there is likely a TSB with that new infotainment version also. I don't have an active GM service subscription currently to check (someone could), but usually when a new infotainment software comes out there is an associated service note. In that service note, there is a list of all the infotainment things updated, and it references the version number, and how to perform the radio update (SPS and USB).
Here is and example of what it looks like (from the last major update - NOT the SQBR6 we want)...
#24-NA-193: Radio Software Update W52E-176.1.2-M170-SQBR5-250.2 - (May 23, 2025)
... and so on - with change list and programming procedure following.
So if the dealer is actually looking up TSB's for the car model & year, they should know all this. But many only look for active recalls for the VIN (very few of these), as opposed to doing any TSB research for the car family as a whole.