My pressure pad adapter for the tlr-1 has a off/on/pressure pad switch.
of course, but without a master control on the body to fully turn it off, the light can still be mistakenly turned on.
i've had TLRs and other brands (with/without extension "pressure" cords) that have turned on accidentally.
to prevent ALD, companies like surefire X300 & X400-series have this "definitely off" feature.
without a master on/off control, i've found my batteries dead when needed (due to pressure when in a carry case), and also have exposed my position when i didn't want that either.
but that said, the surefire models XC1 and XC2 don't have it either...