Parsing domain from Bitwarden's custom fields

We are using Vaultwarden (same API as Bitwarden).
Currently the RDM integration will take the username & password from Bitwarden without issues.
Bitwarden doesn't natively store the domain separately, you are supposed to put it together with the username field.
However, this means that RDM isn't able to later separate the username & domain to use with the various formats depending on which application you need to log in to.

In Bitwarden we can create custom fields, I'd like RDM to be able to parse one of these as the domain.

I see in the Synchroniser part, there are already some fields pre-populated. I'd like to be able to add one for the domain.
https://docs.devolutions.net/rdm/kb/rdm-windows/how-to-articles/configure-bitwarden-entry/#fields


Would this be a possibility ?