PVoFS v1.0 will stop working after any slo-mo effects in the game.
This is a temporary solution to remove the slo-mo effect from player death and in-game effects like Jet.
This file requires PVoFS v1.0 to be installed as well.

For a bug that I cannot reproduce - the freq remains low after SlowTime effects. If you can reproduce this, use this version, recreate the bug, and send me \Documents\my games\Fallout4\Logs\Script\User\PlayerVoiceFrequencySlider.0.log