Hi! Author here, happy to answer any questions.
I'm in the process of moving all my organization stuff into org-mode. This includes agenda, todo lists, project management and notes. This is a long process with a lot of fine tunings and try/errors. But, for me it's like what you said about writing : it's in the process of doing it that you think. This helps me understand my actual needs. And emacs/orgmode is so powerfull and customizable that it's a very goos tool…
> My question is : in what way should I modify my current note files to be compatible with org-roam ?
In contrast to zetteldeft, the links in org-roam are real file links. This means you need to replace all of the zetteldeft links with actual org file-links.
That should be all the changes required I think.