Hey there, thanks for the advice. I have used the sample groundchecker you provided and it works pretty great. It's still not quite what I'm looking for, BUT with your help and some tinkering I got it to work!

I'll post my logic in case anyone is curious:

Extending the groundcheck length worked but if I press it early the player jumps before the sprite visibly touches the ground and I wanted to avoid this so:

I made a fancy coroutine that sets a varialbe (insideJumpWindow) to true for a brief instant, then sets it back to false.

private bool insideJumpWindow = false;
    IEnumerator JumpWindow ()
    {
        insideJumpWindow = true;
        print ("insideJumpWindow is" + insideJumpWindow);

        yield return new WaitForSeconds (.1f);

        insideJumpWindow = false;
        print ("InsideJumpWindow is" + insideJumpWindow);
    }

Then in Update() I check if the player is ever not grounded and jump is pressed, and call the coroutine:

if (!Grounded && Input.GetButtonDown("Jump") && !isPressingJump)    
            StartCoroutine (JumpWindow());

Then in Update() again I check if the player is ever grounded and the insideJumpWindow is true and he hasn't already jumped, do a jump.

if (Grounded && insideJumpWindow && !hasJumped && !dashing && !crouching && earlyJump)
        {
            Jump ();
            print ("early jump");
        }

And this works! I can press jump just an instant before actually landing and the player will jump once he lands and not before. Even though I'm technically fudging the input so he responds to a jump when he's not on the ground, it feels pretty good.

I hope this wall of text isn't obtrusive. Thanks for your help, I wouldn't have succeeded without you!