The cocking indicator should be up/exposed when the striker is cocked,,doesn't matter if the safety is ON or OFF.

You can relieve the mainspring tension on the 1899/99 by closing the lever and at the same time holding the trigger back.
It takes a little practice as the last little movement to skip the trigger & sear past the striker uses a bit of trigger manipulation,
But you can pull the lever shut and locked on an EMPTY chamber for storage and have the mainspring relaxed. Some folks like that idea.

Don't do this w/a round in the chamber as the firing pin will be down hard on the round/primer in the chamber.
The round will just be ejected anyway as you lever the gun to cock it so no advantage there anyway.