Append value to property that is used in a form

Hi everyone,
My company makes use of a hidden field in the top of marketing forms that captures there current interest.
The problem we experience is that the value will overwrite the previous value. In case the form submission is the trigger for the workflow it is allready to late and the value will be overwritten. Is there a way to append this value to the existing values?
It does occur that someone converts multiple times in a month and shows different interests. This makes reporting hard as the interest property will only display the interest from the last submission.

For now i made a workflow where the value with the (new) most recent interest is appended to a property that collects all a contacts interests. Not just the most recent.
This brings his own difficulties as these interests will accumulate and it is harder to tell when this interest was shown. You can see all the forms someone submitted, the most recent will be on top. But i am only able to see the date for the most recent conversion as this is a date picker field as well that will be overwritten on every new form submission as well.
In the ideal situation I can report on all conversions, divided by interest and date of conversion. Now the best I can do is the most recent conversion date + conversion interest.
Is there a better way to go about it? Or is it sometimes just nog possible to append instead of overwrite?
Best Regards,
Max

Hi @Max-Wolters,

Generally, appending to a separate property is the correct way to go here, yes. To see the history (when working the contact), one would look at the property history: View a record's property history

For more detail, we’re entering custom object territory, requiring an Enterprise subscription (ideally*). For each form submission, one would create a form submission custom object record (via a contact-based workflow) and pass through the interest. That way, a contact would be associated to those submissions, they would be visible through the right sidebar as associated cards, and the preview on those cards could show the interest.

Best regards!

* With HubSpot’s new data model, theoretically one of the existing new objects (appointments, listings, services) could be renamed and “mis-used” as a form submission custom object. I can’t say I would recommend it but it’s theoretically possible.