I don't know how to reasonable predict ARV.

The latest forecast I have from Axiometrics predicts a reversal of absorption in 2020 but then back to positive absorption in 2021 and 2022. 

No one can predict a recession.

I don't predict specific future events, doing so would make me a propagandist. 

“Near the end of expected life” is a vague opinion and I’ve never seen a disclosure form that requires a seller to predict when something is going to go out. 

...all the "experts" that were predicting it for the last 10-12 years will be pointing to the drop and saying, "I was right...see I told you so"...completely ignoring the facts that they were wrong the previous 10-12 years.Suggestions when it "does eventually" happen?...

You cannot predict which listing site will do well for you at your location without significant testing. you also will generally get about 7% are the people coming and finding you and your website if you make it reasonably clear.

Is there a method to accurately predict arv accurately without having to leverage your own years of experience?

Ken I also, feel is very right with saying "while it last" as we can't predict the market.

But its hard to predict that type of thing and i personally don't like to count on it.So you may want to find ways to look off market to find a decent deal.