iPaaS Forms: Updating 'ComboBox' component's 'Choices' property with flow

Hello,
I have a ComboBox component in a form, and I want it to initialise, once the form is loaded, with a set of values given by a flow.
I've set something up in the 'Conditions' tab of the component's settings, and the flow is indeed being called, but the rendering of the component is incorrect.
When the flow returns a sheet with two columns, the text of each dropdown item is '[Object object]' when selected, but 'undefined' when the dropdown options are actually viewed.
When the flow instead returns a list, each option shows up as 'undefined', until clicked, when the text shows the list item instead (the list only has a single column/property to it, which is not what I want regardless of whether or not it rendered correctly; I'm hoping to have the ComboBox present a series of choices with some Text, but to return the selected Value associated with that choice when the form is submitted, with both the Text and matching Value coming from the flow).
When the flow returns a table, with 'Text' and 'Value' properties, the same exact situation as with the sheet occurs.
Is this component only intended to have its choices filled in manually, by hand, while designing the form?
Thanks