Are you sure on the anti seize? Is the 58 ft/lbs de rated for anti seize?A chain stretches very little when new and never after that. Chains wear when the lube that is installed at the factory leaks out due to worn o-rings or abuse. There are parts of the chain that do not have factory lube and must be manually lubed, maybe every other tank when running in dry weather, and every tank of gas when running in the rain or off pavement.
Once the chain is correctly adjusted, expect it to run many, many miles before another adjustment is needed--if you lube it adequately.
A few tips--
--The marks on the swing arm for rear axle position are not to be trusted. Sight down the chain (or use an alignment gizmo) to get the rear wheel correctly aligned with the front sprocket.
--Give the chain the amount of slack shown in the owner's manual. A bit loose is better than a bit tight. Remember that the chain tightens when the swing arm goes up, and too tight wears the chain very quickly.
--Put the rear axle in from the right. It is easier to keep all the parts lined up.
--Put some antiseize on the axle threads and torque the axle nut to about 58 lbs-ft.