Sorry, but no update on the release date for a macOS firmware tool yet. I definitely don’t want guess and give you a date that we can’t meet.
As stated in the Four Methods post there is a risk to damage your Spectrum. So as awful as it is waiting patiently, or even waiting impatiently, we recommend waiting for the macOS update tool or borrowing a windows 10 PC to complete the firmware update.
As members of the community have pointed out you can install windows on your M1 Mac - but the process is not as simple as it was using Bootcamp. I’ve read the instructions and I would advise to proceed with caution if you decide to try it. Make certain you understand each step and the risks involved. The same advice for upgrading via an emulation layer like Parallels, Crossover or wine. Other users have reported success but neither of these methods are the recommended firmware update process.