The footnote on the Digital camera RAW formats supported by iOS 11 and macOS High Sierra living document show a footnote (3) for this camera that points to Uncompressed Raw Format only. Which is what you have stated.
Apple and Fuji do not coordinate with Adobe (Lightroom?) and as we saw with the Nikon D850 in Dec. 2017, only after another patch arrived for the just previously released 10.13.4 — were raw images suddenly viewable in Finder, or Photos.
As this is a user-to-user site, you won't be receiving any help from Apple for this unless it is again, suddenly fixed in another Security update, or included in the 10.13.6 update that will likely arrive next month. We have no way of knowing if the issue you mention is a deliverable, or even if Apple is aware.
You might submit a bug report using your existing Apple ID, or send feedback to either the macOS, or Photos product team via Apple's feedback landing page.