I noticed a probably unintended side effect of adding the chair indicator....
Ok, prior to chair indicator, i divided my friends list and "harvested" (sat in chair) early morning, noonish, early evening and just before bed.
I upgraded flooring to 2nd best (20% to get 25 extra coins when sitting at others' tables). And it actually proc'd quite often.
However, with a chair becoming available in any of my 128 friends so spread out time-wise (since everyone of their friends can see the open chair indicator and pounce), a tavern is almost full to full at any given moment (depending on size of table). So, instead of 20% of visiting 30ish tables, now each visit is a single event spaced well apart from other visits.
So, it turns out it is WASTED money/coin to upgrade your flooring because that 20% chance RARELY procs...
So, if you haven't upgraded your floor alot, DON'T. you will maybe see it 4-6 times total a day now typically, unless you have alot of friends with open seats open at the same time.