The Metamask address through which you register is crucial. You will be able to arbitrate the deal only with that address, and someone will be able to impersonate you if they have access and control over your Metamask address.
Apart from the initial invitation to participate as an escrow, all other communication should go through the Zenland platform, where all parties are also logged in with their Metamask (addresses).
A fairly good and functional platform.
When I was applying yesterday as an escrow agent, they did not ask me any Metamask address. I thought I will be asked. I have not receive any response on my forum PM and Telegram yet since these are the two communication channel they received from me. It seems you are already with them. Am I going to the right direction?