They are only extremists until disaster sets in…then they are permanently crippled with massive amounts of regret!
That said, I think it can be done if the ring is soft and allows some circulation.
The best way to determine if its safe is to wear it during the day for the same period of time you wish to wear it at nite.
Check frequently to see if you get coldness or discoloration (darker). Make sure you wear it for a prolonged erection to see what happens.
If you find you can do all the above, and you maintain good color and temperature (normal) then I think you would probably be ok.
There is still the possibility of sleeping on it in a way that could be deleterious, but if its soft material, I think that is a very small chance.