It would be great if we could just link svg files, rather than embed it, just like we do with images. It is indeed not convenient to have to import a new version of an svg file everytime we make a modification to it.
I create first a link annotation, choose the type URL and write the web address into the Destination field. Then I write into the link annotation box, the text of the link. Into Scribe, I see this text but when I create the PDF document, the text is not visible but the link annotation is present. When I pass the mouse on it, it changes into a hand. A click, or double-click, open the navigator at the right page.
when switching from 1.4.x to a recent 1.5.x you need to double check the layout of the text for overflows (or underflows or other change that might be relevant to the context)
if you did work in a clean way, it should be easy to check for overflows (which are the worst offenders, since parts of the text are not been shown) by running the "preflight verifier" (the check tool that is been shown when exporting to pdf...) and make sure that it does not show any warnings.
from discussion with craig and jean, the problem is related to library scribus uses to layout the text, which does not make any guarantee on the metrics across versions.
there is no problem with installing 1.5.8 parallel to 1.4.8 on mojave tocheck the compatibility before you switch to ventura. i'm not sure if the new text engine of scribus 1.5.3 an newer will change something... as i'm already on ventura, i cant check it. but i had no issues with old files so far...