In 2018, no you would have failed for sure.
In 2019, yes you probably would have been fine.
In 2020... ???????
With the utter nonsense in the reliability and consistency of these exams and the statistical voodoo of how they are graded, combined with the fact you can only take them once every 365 days, why in the world would you risk it?
The new normal is wasting months rather than weeks overstudying for these exams. You should at least read McDermott all the way through, understanding everything and taking notes, and ideally doing the chapter questions. At least the physics knowledge is fundamentally more practical for us than having to waste time learning most of bio, which is about as related a discipline as contract theory or something (probably more useful).
Just doing a couple of Raphex exams and hoping for the best is a fool's errand. You're going to be leaving a lot of holes and missing core concepts by doing that. Sorry.
Edit: For reference, I read McDermott cover-to-cover, taking time to understand and digest every word. Then I did inservices and 3 raphex exams, and I barely passed in 2018. I was always consistently 90+ percentile on inservice too. Don't underestimate the basic physics component (the first few chapters of McDermott). They LOVE to pick out random facts from that. For basic physics, you have to go a little beyond grasping fundamentals to outright rote memorizing particle s---.