Can VVDI MB do 2013 GL extra key?

Yep. you can do it with VVDI MB, if you have read EIS data.

X166 chassis has a W166 EZS and password can be calculated if not FBS4 (late 2013 onwards) if you have managed to read EIS data already it’s FBS3 and you can get the password no problem at all.

Btw, Operation timed out is due to server issue at the time. Re-upload acquisition data and you should get a response with your password. No need to remove anything from car, all by OBD.

Tech support from Xhorsetool.com