Are you applying to be a PR via spousal sponsorship? (your spouse is a PR or citizen and applying for you to become a PR)
Or are you applying for a spousal visa of another person who is a current study or work visa holder?
These are very different processes.
For inland spousal sponsorship, you can apply for an open work permit when you submit the spousal sponsorship application. You will need an open work permit to work. If you do not plan to work after your working holiday visa expires, then you do not HAVE to apply for the OWP. There is no "exemption" of the OWP application.
Spousal sponsorship doesn't give you permission to work until it's approved and you became a PR.