A lot of this annoying behavior would be curbed if the lounge agents actually walked thru sometimes and provided some polite 'guidance'. Its not really for us users to correct others in the lounge. I do not have to tell other patrons how to behave in a restaurant. I find they stay behind the check-in counter and the only staff wandering are the F&B staff who obviously are not going to correct behavior as thats not their role. Not looking for lounge police but a friendly CS agent would do nicely.
I have been in UC lounges and seen agents come up to people and tell them to remove their feet from the table and also to use the booths for loud calls.