Is there any way to scale up canvas with TextBox without pixelating the TextBox?

Hi!

I am working on inspection system where the user should have been able to zoom up document (A4 format) because its unreadeable in its default size and write some data (names, numbers etc.).

My first idea was to scale up whole canvas (picture as background (= document) and all textboxes (= fill)) through Set Render Scale. But this way showed up unusable because textboxes and all texts become blurred due to their small original size (background picure is okay).

Is there any way to enhance quality of textboxes/texts during scaling them up? I would normally do that through font size, but then I am unable to keep them in right place of document background.

Thanks for ideas!