I went through a rather thorough tutorial series of Roam Research (RR) on YouTube.
My personal view:
DT is a document(of multiple formats)-centric app, while RR is a data-centric app. A file is a basic unit in DT, and text entry is a basic unit in RR. IMHO, the logic of workflow of the two different designs - at a database level - probably won’t mix well. Notes management is only a subset of DT.
DT is an open system of files. IMHO, the main job of a DT database is to keep track of the static and dynamic linkages between files (by the index of tags and groups and to Finder and by links and similarity). RR is based on a proprietary data management system. The main job of RR is holding the data(each text entry) and keeping track of their tags. I hope RR is not putting all bits of text entry in a single file and load it into memory for performance (unlikely the case)!
If we deconstruct how linkages and views in RR works, it’s based on tags and table of tags. Each entry has a minimum of one tag (date tag is the anchor), and a view in RR is just the table/list of data of each tag. While RR claims the link as a two-way link, it’s only presenting the merge view of text items within a tag. So a view in RR is almost the same as a merged view of list of files in DT’s tags cloud with a more sophisticated tag filter (tags is and tags is not).
I’m not trying to downplay RR, the app has a lot of interesting ways to present the merged view in a tag or combination of tags. I believe that with a little twist of MVOutline script, plus a few utility scripts, can achieve the most basic function of RR to a designated set of notes in DT.
Just my 5 cents. My ancient training in computer science can mislead me to totally wrong judgement.