Add JS option "async"?

Well … That is theoretically possible, but if one considers that Autoptimize aggregates all JS-files into one minimized file which is loaded at the very end of HTML, the advantages are minimal, no?

Yes, maybe you are right.
And what about later parsing?

https://developers.google.com/speed/pagespeed/insights?hl=en#url=http_3A_2F_2Fwww.peleke.de&mobile=false&rule=DeferParsingJavaScript

probably same remark as for async, but I’ll add testing with async & defer to my todo-list for a future version ??

Okay, thanks