Do what ever makes you feel comfortable.
I've answered this numerous times before, but here's the answer again.
Loading magazines to intended capacity and leaving them that way does not weaken or damage the magazine spring as long as the spring was designed to handle the capacity of the magazine.
What weakens springs is overloading of a springs intended use and the continuous loading and unloading of the spring in normal use.
Best Regards
Bob Hunter
www.huntercustoms.com