How sticky and stiff should the finished marshmallow be when you pour it into the tray?
I usually whip mine to ~ 10 - 12 minutes.
When i pour it in the pan it is very stiff and sets up very quickly. In fact, the word pour has nothing to do with it- very much a scrap and cajole process.
The longer you whip it, the more air you incorporate, the more chance you give the syrup to cool and stiffen the mix.
I think your flavors (passion fruit!!) are begging for colored swirls .