Properties for uxml component templates?

I have designed a component in the UI Builder that I have converted to a Template. This template component contains a label. The parent should be able to change the text of this label.

However, instead of trying to figure out the query to this label in the template, I would like the template to expose a property instead.

Is it possible - either in UXML or by somehow extending the template with code - to add a property to template components?

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