Vase mode can't create a 'top' surface, so the gaps in the fins are not surprising. What I didn't expect was that the pointed nose works so well. A previous print sliced with Cura ( and a different, very simple printer ) handled the fins perfectly but put a dimple in the pointed nose.
Just tell people that the holes in the fins are deliberate: inputs for intergalactic particles to fuel the rocket.
The first one I printed had the same issue, I changed the line width to .63 and now the holes are filled in and it's a bit stronger. Still used vase mode.
This was a fun test of Vase Mode. The surface quality with Bambu PLA Tough was really good. There was a tiny blob at the very top, that I removed with sandpaper. Also, the extreme overhang at the top of the fins ended up with little gaps. Great little rocket!
Fun quick print. But fase mode? don't touch it to much or the print will break.
imho, much better to add some walls and add some print time, will deliver a way more robust print.