Btw, noticed someone else replied with a link to Reddit where they discussed what to change, supposedly.
That was at Disable "To get future Brave updates, you'll need Windows-10 or later" message - #27 by pierredekat
And instead of just linking to a place where they then link elsewhere, the Reddit is https://www.reddit.com/r/chrome/comments/z9ay1h/how_do_i_disable_the_to_get_future_google_chrome/
So there may be that, though I’m still hoping to learn more directly from Brave later in the week.