During a 3.05 → 3.07 firmware update, started via the Ubuntu software updater, the screen of my Laptop 13 (AMD Ryzen 7) went black. I waited four or five hours, did a hard shutdown by holding the power key, and then turned the laptop on again. Thankfully, the laptop booted normally, and dmidecode reported firmware version 3.07.
My issue is very similar to the ones reported a year ago, here and here, for 3.03 → 3.05 updates. Many thanks to @Marcel_Birn and @Maksym_Vlasov for their reports and recommendations!
For more details, see the firmware issue I just filed. I’m posting this as a warning to anyone else considering a firmware update.