Help/Advice for Week 10 of Build Me Up training plan

I am in week 10 of Build Me up and have completed Baffling Beau (73 TSS, VO2 max workout) and Potpourri (64 TSS). My next workout is Exemplar which has a TSS Of 73. The description says it is one of the hardest workouts but when I look at the plan it is all zone 3 and 4. If it is truly hard, I will take a rest day before doing it. But if it isn’t I will do it tomorrow and save the rest for between the two 90 minute workouts with VO2 max sessions as part of them and TSS of 111 and 121. I am trying to finish my week on Saturday so that I can rest Sunday before starting the hardest week of the plan on Monday. My other question is how do you know how hard to push for your FTP test at the end of week 12? Is there a % of FTP to shoot for that is typical? Thanks in advance for your suggestions. They have really helped me to get through this plan.