How can I add delay to the inertial bounce expression? (HELP!)

You have the attention of three reknown expression experts @dnnmarr, did their suggestions help you?

You would simply have to add a temporal offset to the p.key(n).time for each layer. Something like p.key(n).time+framesToTime(5).

Mylenium

I would create an expression that performed the entire movement based on the layer in and out point, then stagger the layers in the timeline, so they came in one at a time. 

You could also use the layer index as a multiplier for the move start, speed, or end of move time.

You could also set up a second slider to use as a delay slider. 

I have a lot of animation presets that move layers in and out of the frame. They almost all use layer in and out points for the move. You put a layer where you want it to end up, add the preset, which usually adds a bunch of sliders and check boxes, then sequence the layers, and you're done.

I don't have time to work it out for you right now, but if you want all of the layers to move in following the parent, then bounce to a stop at different times, then the move timing will have to be controlled by the time of the last parent keyframe + a time delay. 

Here's my FlyInBounceFlyOut expression. You might get some ideas from the language. You'll have to add some sliders and a checkbox to make it work, but it might give you some ideas.

sif = effect("slideIn Frames")("Slider");
sof= effect("slideOut Frames")("Slider");
// find in and out pointOfInterest
stime = time - inPoint;
inTime = sif * thisComp.frameDuration;
	if (effect("Match SI SO")("Checkbox") == 0) {
	outTime = sof * thisComp.frameDuration;
	}
	else if (effect("Match SI SO")("Checkbox") == 1) {
	outTime = inTime;
	}
// Fix  layer size when scaled
sf = scale - [100, 100];
xSize = width + (width * sf[0]/100);
ySize = height + (height * sf[1]/100);
realSize = [xSize, ySize];
// Set Positions
spx = 0 - realSize[0] + realSize[0]/2 ;
rstx = value [0];
rsty = value[1];
epy = thisComp.height + realSize[1] - realSize[1]/2;
// create movement 
freq = effect("bounce Frequency")("Slider");
        amplitude = effect("bounce Amplitude")("Slider");
        decay = effect("bounce Decay")("Slider");
    posCos = Math.abs(Math.cos(freq*time*2*Math.PI));
	nt = time-inPoint;
    y = amplitude*posCos/Math.exp(decay*nt);
moveIn = Math.min(linear(stime,0,inTime,spx  ,rstx-y));
moveOut = Math.min(easeIn(time,outPoint - outTime,outPoint - thisComp.frameDuration,rsty ,epy));
[moveIn, moveOut]

What defines how long the delay is for each layer?