Again a self explanatory title but maybe a simple approach to form creation.
Allow a scan to PDF and allow a user to create transparent textboxes linked to a data field over the scan image.
This will create PDF forms from direct NextCloud data and app fields.
I would say Libre but for some reason Libre still has to adopt a suitable archive format such as searchable PDF.
If this is possible in Libre then the same process but Libre.
Some form of simple data driven form creation, really 