My bad!
I had seen the mega-thread "Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes" when I joined here last year, but never managed to read through it. But I finally did now, and, yes, the answer is there.
"Uboot-OS Version:
8.1"
does indicate that the OS is version 1 (disregard the "8."), and when the OS is updated to V2, it would show 8.2.
Thanks for the push! I learned a lot more about the scope in the process.
(Now to rest my eyes after reading through 80+ pages.)
But before I do that, I did the OS update; Took just a few seconds from powering on, to complete. System Status now shows 8.2. All good.