"Personally I do use the arrow operator as it (subjectively) stands out more clearly to me in an eye-parse."

Yep, me too.

I like being able to understand code at a very quick glance, and at a quick glance, I would (and do) see $$var{thing} as a hash, not a hash reference. $var->{thing} is very unambiguous and doesn't require a second look, ever.

Because scalar references are so infrequently used, I would expect to have to look twice at a variable with the double $$ to understand why the author has used one. An in-memory variable-based file is one example, and is a special case that often does require a bit more than just a glance.