Shifting second set of keyframes with marker

Hi there!
AE expressions have been something I've loved tinkering with but have, self admittedly, still had a hard time grasping at points. I've recently been trying to shift the second set of keyframes in an animation by tying them to a marker. I'm creating a graphics kit with a lower third that animates in - rests for a few beats - and then animates out. My hope is that I can set up this marker so that when it's used the marker can simply be shifted to fit various timing needs.


I've included an expression I've been using for attributes that have no keyframes coming before it.

Any help would be GREATLY appreciated!
Thanks,
Billy

**Bonus Question**
Some of the 'exit' animations are happening at slightly offset times (2-3 frames). Without dealing with pre-comping and then time-remapping - is there a way to have a marker have an offset built in?

L= thisComp.layer("CompControls");
m = L.marker.key("Out");
if (time < m.time){
valueAtTime(0);
}else{
t = time - m.time;
valueAtTime(key(1).time + t);
}

Might also help: http://workbench.tv/tutorials/2017-08-11_Semi-AutomaticAnimation/

I borrowed a ton from Dan but approached things differently.

Joe Clay
Workbench.tv

Dan - you're a legend. Works like a charm - much obliged!!