robertg2 That's the point, for me the destination values on the seaport help site are 100% correct (cannot say for Iron mill because I do not upgrade this one 😉). Only Grove - formerly known as Bamboo - went through so many changes that it is still messed up.
LockDog For some destinations the travel times at lower levels are shorter, they will increase when progressing. But, I agree with you, it would also be nice to know at which levels and at what rate they increase.