I currently have 2 lcd boxes in use, because of this (I help quite a lot of people at the track with the HW ESC's).
If once upgraded the box to V1.08, you can't go back I believe.
If you have another box with V1.07 on it, you can still go anyway you want.
I don't know the older available ESC firmwares in V3.1 software, but the following steps should work I think:
With 3.1 software, and V1.08 box, flash the ESC to 930STOCK (or any firmware you know also exists in V1.64), then with 1.64 software and v1.07 box, flash the ESC to V2_508 no timing.
Note:
You can have both V3.1 and V1.64 (there are a few) and V1.63, 1.62, next to eachother on your PC, just unpack them in different folders!
Why bin it?
And also buying a 2nd box should not be a real problem, because they are not that expensive (Checked the box from Orion?
)