Is there any way to link two textboxes?

My use case is really simple: two textboxes need to contain the same text at all times, although styled differently. It would be nice to have an option to link them somehow, or create a reference to an existing textbox, or something of the sort.

Perhaps even an option to set variables for a project or something like that. Create a variable text in some variables panel, input $text$ in any place where it’s needed, and be able to change it from a single place.

If you would like to edit two text blocks from a single place, I would recommend using a text styles feature. You can save text styles to the document assets and reuse them across your project.
You can find out more details on this feature in our documentation.