Fixed or adjustable shelves?

I am considering whether to have permanently fixed or adjustable shelves for the 27.5" tall cabinet at the foot of my bed, and the upper galley cabinets. I "think" I prefer adjustable shelves. However I wonder if adjustable shelves are likely to come loose from road travel and bumping?
Tools I might use to make the holes for adjustable shelves include:
1. KREG KMA3200 Shelf Pin Drilling Jig
2. rockler.com/bench-dog-shelf-pin-jig
3. JIG IT® Shelving Jig w/Self-Centering Bit Probably too pricy for my limited needs.
4. Or a home made jig
I'd appreciate your experience with fixed and/or adjustable shelves in a teardrop trailer. Which do you prefer? Why?
edited to add that 27.5" is anticipated height for the cabinet at the foot of the bed. This is the cabinet I am more likely to want adjustable shelves in. Not sure if I'll want 1 or 2 adjustable shelves inside it.
Tools I might use to make the holes for adjustable shelves include:
1. KREG KMA3200 Shelf Pin Drilling Jig
2. rockler.com/bench-dog-shelf-pin-jig
3. JIG IT® Shelving Jig w/Self-Centering Bit Probably too pricy for my limited needs.
4. Or a home made jig
I'd appreciate your experience with fixed and/or adjustable shelves in a teardrop trailer. Which do you prefer? Why?
edited to add that 27.5" is anticipated height for the cabinet at the foot of the bed. This is the cabinet I am more likely to want adjustable shelves in. Not sure if I'll want 1 or 2 adjustable shelves inside it.