The rules
The rules are clear, if you fall more than 5 feet, you take damage, it does not matter how you got that high.
The reality
Realistically, if your bones, tendons and muscles are strong enough to propel you to X feet in the air, they are definetely strong enough to absorb the shock of falling from X. I can easily jump from 5 feet, but have no chance of jumping to even 4 feet.
Basically, the rules are wrong in this regard. This is not just PF2, DnD does the same for example.
Obviously, this does not apply to Blast Boots, but I would expect the Boots of Bounding (or any magic item) to deal with the landing as well as the launching.
The solution
House-rule fix
If I were your GM, I would just house-rule that you cannot hurt yourself with a muscle-powered jump unless your fall is more than how high you could jump to without an actual roll (so Assurance included).
Official fix
The Cat Fall skill feat can help with this:
Proficiency |
Fall reduction |
Deals with |
Trained |
10 |
Highest jump without feats and equipment |
Expert |
25 |
Blast Boots (Moderate) |
Master |
50 |
Blast Boots (Greater), Cloud jump |
Legendary |
any |
Blast Boots (Major) |