Hi Ursula,
One idea that comes to mind to me would be to make use of a custom data rule on that table and build the rule so that the Pipeline creating the record isn't stopped from creating but future edits are. I do that in custom data rules by adding a condition that the only time the field being blank is ok is if the Date Created and Date Modified field are identical upon save. This means when a record is created I am not making it required but any other time they are going to get stopped if that field isn't filled in. I have an example of a rule like this with an Address field below.
If([Address Field]="" and [Date Created]<>[Date Modified], "You must include an address on each company record")
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Evan Martinez
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