Cooper,
Thanks for helping us see how we can create more analog & vintage sounding effects.
Some years ago, I was reading a recording techniques manual that described how to enhance the major harmonic overtones of time-based effects, while minimizing background harmonics which disrupt or muddy a guitar signal...
The manual suggested using prime numbers (1, 2, 3, 5, 7, 11, 13, 17, 19, etc) that reinforces the harmonics and reduces background harmonics.
This also adds to the vintage sound of an effect, and helps preserve the quality of the effect as well.
Here are 2 pages of the first 1000 prime numbers. I usually prefer a delay time between 300 and 400 ms, and there a plenty to choose from.