Q.Do Packaged Passion Flower Seeds Benefit From Cold Stratifacation Prior To Planting?
Zone 5b Starting seeds indoors

Certified GKH Gardening Expert
Passion vine may not be hardy in your zone 5b. It is generally hardy in zone 6 and higher. If you plant them in a protected area near the house they may return each year. Mulch well before winter.
You can start the seeds indoors about eight weeks before the last frost. They do not need cold stratification but if they are dormant you may need to soak the seeds for 24 hours and remove the floaters. Seed germination can take three weeks or more. If you are anxious for blooms you may want to purchase a mature plant in spring.
https://www.gardeningknowhow.com/ornamental/vines/passion-flower/propagating-passion-flower.htm