Springs do not "relax, weaken, or become more forgiving" just from keeping the mag loaded all the time.
That is an "old wives tale". Springs relax and become easier to load by full cycles, load/unload. Over and over again.
I was told that as a kid by my career Army dad and older brother that was a detective. Others had told them that.
Rotate your mags, don't leave them loaded more than a few months.
But now we know better. Ask anyone with an engineering degree or a machinist.
Patrick Sweeney, who has engineering degrees, and is a custom gunsmith, competitive shooter and LE instructor, said an old lady brought a bunch of guns into his Michigan shop and wanted to sell them. Her husband had died and she wanted to get rid of the collection. There were thousands of rounds of ammo, all loaded in magazines. She said they had been loaded for 30 years. Sweeney said the mags all worked fine when tested later.
Once again, keeping mags loaded (spring compressed) does nothing to relax or weaken the spring.
What does is loading and unloading them over and over, either unloading by hand, or by shooting the ammo in them.