F5 exemption and opting for P5

I got an exemption for Paper F5 but now I want to opt for Paper P5. Would it be advisable to get the F5 text in addition to the P5 text?

My primary concern is that I would end up spending too much time on the F5 text and eventually have very little time for Paper P5. Since its already September and I also have Paper P7, I’m wondering if there is some way I can skim through the F5 key concepts and then get started with P5. I do have some cost accounting knowledge regarding variances,budgeting etc.

Any guidance/tips would be highly appreciated.

Thanks

Omer