FYI comment type would not have anything to act upon, they are only as background information.

The value into classifying comments to be as "suggestion" or "FYI" is from the perspective of UX, the "FYI" ones would be designed to occupy less space and be less intrusive.

In parallel, we could have two forms, one as a small "(?)" button and a full line, then an expanded view, potentially with non-text metadata (a use cases includes graphing information or URLs).