I installed a new SSD and was actually able to find original driver downloads for the laptop (on Sony India website for some reason). Since I was installing all drivers and utilities from scratch I also decided to update the BIOS.
The update part completed successfully...
However after this step the setup utility got stuck trying to restart the laptop. Since this was a BIOS update, I didn't want to manually reboot the laptop in case the BIOS was actually corrupt, but after leaving it for around 30 minutes, I ran out of patience.
I terminated the process for the BIOS update tool and restarted the laptop. Going into the BIOS showed me that I did in fact have the latest R0240E6 version. Not bricked after all. From this point the laptop proceeded to boot OK too.
I'm not sure why the setup utility got stuck, but since the update part was successful I think it's safe to say that a manual restart was definitely the right step forward (or I just got lucky that the laptop was bricked 😅).