It's not possible to get content from multiple fields mapped into an ORCID field

[olli-gold]

Is your feature request related to a problem? Please describe.
For conference contributions, we would like to send the name of the conference to ORCID, when the item is pushed. Under DSpace-CRIS 5 this was possible with the orcid-work-metadata.properties configuration. But under DSpace-CRIS 7 that has changed.

This worked under DSpace-CRIS 5:
orcid-work-metadata.properties:
orcid.journal_title = dc.relation.ispartof, dc.relation.conference

Under DSpace-CRIS 7 it's not possible to set a comma separated list of metadata fields in orcid.cfg.
Neither this works:

orcid.mapping.work.journal-title = dc.relation.ispartof, dc.relation.conference

nor this:

orcid.mapping.work.journal-title = dc.relation.ispartof
orcid.mapping.work.journal-title = dc.relation.conference

Describe the solution you'd like
I would like to be able to set the journal-title on ORCID side with multiple metadata fields.

Describe alternatives or workarounds you've considered
I considered using a virtual field for that and to submit just the contents of this virtual field. But I guess that's not what the virtual fields are designed for at all.

Additional context
None