Hello again, so I stumbled upon an issue with default value of freeform text field. I'm setting it with formula, which is

{record_id.field_id}

(where record_id is custom multiselect field on a form, sourced from custom record). This should take value of

field_id

from custom record, then populate the text field on a form. The question is - how to make it work with multiselect, when there is more than one option selected? (it works fine with one option selected only).