Is there a difference between “modest” and “moderate”? Thanks for help!
When taslking about an amount, rate or level of something (which I assume you are because you are comparing those two words), then there is very little difference… a modest amount can be thought of as a slightly smaller than moderate amount of something.
“modest” originates from the word “modestus” meaning ‘keeping due measure’; “moderate” from ‘moderat’ - ‘reduced or controlled’. Having become English words, “modest” describes an unassuming or humble state while “moderate” means average in amount, quality, etc., in most instances, and interchangeable for the rest.
Simultaneity. 
What a once-regular visitor would have called an ‘air miss’ - but you put it somuch more eloquently.