Do you use the trem lock when you change or temporarily take off the strings?

[supersonicjazzmaster]

Never.

But changing one string at the time I don't really experience a problem.

I would like to give the same comment:
Never.
But changing one string at the time I don't really experience a problem

[alexpigment]

A lot of one-at-a-time string changers here I honestly never do that for whatever reason. Having said that, I do work on my guitars' electronics from time to time, which requires them to be all off temporarily (and I use the trem lock in this case). And of course, with vintage tuners, you can quickly & easily put the strings back on when you're done.

Other good uses for the trem lock - alternate tunings, at least when it involves multiple strings. I never use it with drop d tuning, even though the other strings technically go out of tune some small amount.

[JagWire]

I had mine setup for proper function but never actually engaged it for any reason. Now I just have the slider so tight it won't slide, this prevents it from loosening over time and rattling from string vibration, it's merely cosmetic now.