@aerys You can uncheck "Do PM Checklist Actions" (see screenshot above by @Graeme_77). The FO won't interfere with your aircraft. However, whenever there is a FO action, he will just "check" all of them. If you are not fast enough, he will continue the checklist. It is not like with Captain actions where he will wait for you to complete them.
I took note of all FO actions and do them beforehand. Thereafter I start the checklist.