Loading and unloading your mags does more harm than leaving them loaded.
The springs have no issues remaining compressed or relaxed. Cycling them is what wears them out.
, a mag that is used often, like your range mags vs. your carry mags MUST
be cleaned and lightly lubed (for protection, NO
grease!) when dirty. This depends on how dirty the ammo you use is and how many rounds you've cycled.
Get a caliber specific mag tube brush. Think of it as an investment.
Magazine Brushes - Brownells