Half understood nonsense.
To say that "the Haas effect" means sub-millisecond delays is inaccurate.
there's NO magic way to stereoize a mono signal, Every benefit has a price. -Go ahead, choose ANY delay from 0.1mS to 10mS, and listen to what it does in mono.
There is no free lunch, anyone who tries to 'authoritize' any approach with a misapplied term either doesn't know what they're talking about, or is being extremely disingenuous.
The Haas effect refers to ambiguity and localization, and is frequently misused as a term. Most people use it wrongly, ten seconds with Google gives a better idea.