Bicycling

I think you can learn a lot about your efficiency and abilities.
Sure, I suppose one could just lift or lower their seat until they felt comfortable, I did that for about 30 yrs.
Worked just fine.
But this is science.
It will help your riding abilities and comfort.
A properly trained technician will understand where you want to be as a rider. They will not try to put a recreational rider into a racing position but they will explain why that position is more efficient.
I say go for it.
When you get home, or even there, take a sharpie and mark the position of everything. Then if you make any changes, you can always move things back.