So while F@H will outright prioritize covid-19 work units (when they are available - they get snatched up pretty fast), boinc (rosetta@home) does not outright prioritize those covid projects.
Rather, it appears that any covid related projects wind up getting submitted via robetta@home. Your server may (will) also work on other project which may or may not be related. Although all of the projects in rosetta are probably of vital importance, if you do wish to prioritize the covid ones, you can go to advanced view, then tasks, and you can suspend tasks that are not given out from robetta. While this still isn't a guarantee that you'll be getting something directly related to covid, at least you can reasonably guess that you're not going to be doing the math for someone who is researching foot fungus.
https://boinc.bakerlab.org/rosetta/forum_thread.php?id=13554&postid=91904#91904
That being said, I'm sure that ALL protein research could quite possibly be of use (if only in tertiary means) for covid research.
Myself, I'm running both F@H and boinc simultaneously. It should also be mentioned that boinc and F@H are NOT competitors, but rather complimentary and each is researching a different thing. As I understand it, F@H researches the mechanism of how the proteins fold, whereas boinc researches the final result after folding. Both researches are necessary in order to completely understand the mechanism behind nCovid-19 and an eventual cure / vaccine.
Unfortunately while F@H will automatically prioritize, boinc requires you to manually do it.