JPM and add-on version

Tried to use JPM instead of CFX today. It works, but I have a question about version numbering.
I have used four digits (2.1.2.0) because I develop for Firefox, SeaMonkey, Chrome/Opera and Safari. The last digit is for minor browser-specific fixes.
Now with JPM/semver I can use three digits only. However, I can use build metadata, for example “2.1.2+0”.
Is this OK or will AMO complain when I upload next build: “2.1.2+1” ?

Moved topic…

Actually, this is a policy of JPM, AMO has nothing to do with it. So you can use whatever JPM accepts.

Thanks.