I totally agree with the last two posts. Ten years seems very reasonable. During your condition inspection we should be looking at the condition of the rubber hoses. What should we be looking for? Here is what the Quest Kodiak maintenance manual says about inspecting hoses:
Fluid Lines and Hoses: Inspect for leaks, cracks, bulging, collapsing, twisting, dents, kinks, chafing, proper bend radius, security of attachment, discoloration, bleaching, deterioration, and proper routing. Check rubber hoses for hardness/flexibility and metal lines for corrosion.


Realize that a manufacture, whether certified or experimental, can only make recommendations for maintaining their aircraft. Only the FAA can make something mandatory. Only the FAA can make things mandatory. On certified aircraft the FAA mandates or approves things via AD notes, chapter 2 of a POH "Limitations" and ATA chapter 4 "Limitations" in maintenance manuals.