I know I'm ready for some outlying NPC elves or Lithians to be spotted by Xukhezur's foremost
optic orb, hurtling at speeds approaching 295 mph.... (520 ft. speed w/ run action) ...which is around the IRL helicopter speed record I used to determine the speed of a previous sentient airship character (a gnome built construct creature) that employed four rotor ducts.
So basically a statistical fly speed of 520 ft. exists as my current ceiling for constructs that are within "
plausibility" for high fantasy settings capable of tinker-style gnome engineering coupled with the magical means to improve one's ability to craft and assemble precision parts and components. In the case of an optic orb, gravity manipulation spells and effects are used as the prerequiste basis for its locomotion.
As it currently exists, it could take an optic orb as few as 6 minutes for it to cover the 30 miles that currently lie between Xukhezur and the majority of the armory plunder he and Lu'Vayla are looking for using a
tracing gem subject to mutliple castings of the spell, assuming it doesn't slow down to examine and inform Xukhezur of any intervening beings, obstacles, conditions or wards that might limit their travel options.
As far as other movement speeds of other creatures go, many animals require revisions to their statistical D&D speeds. Some time ago, I did some looking for Andion's hummingbird familiar, and calculated it should have a listed fly speed of 120 ft. (
Hummingbird Airspeed Velocity). Of course, the speed of a biologically living creature is subject to the limits of its endurance, where as a construct can typically run at its top speed indefinately.