well I never leave a loc on out more than afew months, and even that accoprding to makers is way too long, most say a week is all, and YES that is very short time in a tree
but they claim its the fact the tree grows, and that stress can do major damage unseen to the eye
I always use at least two straps on all my loc on's
better safer than sorry
as for ladder stands, well them I leave out all yr, I tend to loosen the straps at season end, so I can either re snug next yr or replace
I replace straps on ladderstand every 3 yrs, or sooner if need be, and yup, I have two on each ladder too
I also use metal made brases I bolt the top section to the tree with, so it can never pull of the tree, and use extra heavy duty metal and lag bolts, also helps keep stands from being stolen, do this on loc on's too some times
as for support bars on ladder stands
, YES, I inspect and replace as needed, I have had many over the yrs simply rot away, they seem to be made of cheap metals and paint
same goes for the ladders and stand , they are only metal, and metal left in the weather will decay in time
I will admit I spend more time, looking at my taller ladderstands more, due to the stress on the legs, I always feel the BOW in them as there made to work, holds a lot of pressure, so good to keep an eye on them in them area's
and after about 10+ yrs I retire most ladder stands, as figure they served me well, and welds and who know's ?? can be going bad from the inside out, something I wouldn't be able to see, as I know water gets inside them, better safe than sorry my therory