Mstn has made great strides with pdfs. Pdf import and referencing are pretty useful, and recognises that the Mstn user often can not access the originating CAD files.
OTOH, not all pdfs are in vector format. It would be helpful to be able to convert this scanned info into dgn elements:
Text and annotation
Dimensions
Tables
Drawing frames
Drawing Markers, symbols
in addition to the geometric elements like lines, shapes, hatches etc
I think some of this has already been done for PlantSight using AI. There has also been some work on automatic drawing annotation in OpenSite+ that may also help.
iTwins Design Review: reviewing productively is undervalued. The smarter and more searchable the scanned info is faster and more productive the process will be. See Bluebeam Revu. Convert to dgn in addition to re-save as pdf? Partial updates will be common. Also good as a jumping off point for new work in Mstn.
Bentley Asset Analytics play: Drawings are also key assets. Context capture of the physical asset like towers will benefit from any previous drawing info, which will also need to be updated... using Mstn.