I read through a bit of the posts, but I haven't honestly read through them all as I got a bit lost in the mix. To me it sounds like there are two issues.
1. The Rarity of treasure is declining for anything above rare.
2. There are players that seem to be causing issues by automatically assuming they are lending TEs and getting a cut without a discussion.
It was my believe that the treasure was mixed based on the total volume, so there is always a specific percentage for UR, Legendaries, Relics, etc. If that is not the case, maybe TPTB might benefit from a yearly evaluation of treasure pulls similar to the Spreadsheet we as players help populate each year, along with somebody on their side reviewing the remaining treasure to see what was left as I am 100% sure not all treasure is being recorded on the spreadsheet we voluntarily fill out, and I have seen multiple URs & 25k bars pulled but not recorded.
When it comes to sharing TE, unless TD wants to invest in a more tedious process that is more work on them and potential put some players off. It is easy enough to say if you dont have the TE on you for a party member for the duration of the run including epilogue, you dont get the treasure. I dont see any issue with 2 or more players sharing a CoA as long as long as no more than 1 person benefits for the duration of a run, including any overlapping run times. If one person uses it in the morning there shouldn't be something to stop some body using it later that evening, 1100~1200 is not a small price to pay especially when you start adding policies and stipulations. I for one would much rather focus on the toxic behaviors of players that assume they are getting treasure from other players without a conversation. I have extra AoTF,ISSN, & ISGNs I lend out to friends and new players I occasionally ask for a pull or two to help me round out my pulls to get the 50xpull bags, but usually I dont even ask for that. While not the only experiences involving TE & "loaning", I had 2 bad experiences with a specific player during Coaching trying to get me and a friend to use his TE and give him a cut, but when we declined and explained the situation he got very passive aggressive and later acted grossly towards us during the run, during the epilogue of one of the rooms, he "forgot" and demanded, not asked, treasure pulls from my friend who just went on their first run.
Since it was mentioned, below is the Ghosting Rule #7 which specifically relates to TE. I have ghosted twice due to a last minute dropout, and while I think it is worthwhile to make sure TD gets the money they need to keep thriving, I very much dislike when people buy out full runs with the intent to ghost it at cons that sellout in less than an hour like Gen Con. Normally when I have extra tickets I try and find friends who haven't ran before or I think might enjoy the experience, sometimes that means they hand everything over to me and go on about their way but in some cases I hook a new player.
Even though the maximum number of Ghost
characters on a run is nine, no more than five
Ghost characters may receive any tangible bonus.
All Ghost characters can equip TEs if they wish,
but only five Ghost characters receive any
TREASURE CHIPS, token bags, completion tokens,
or other real-world items.
Example 1: If one person buys out the slot of all
10 tickets, five of the Ghost characters can have a
number entered in the Total Treasure calls on the
Party Card, but four are left blank. The real
player’s TE bonus is, of course, that of the actual
solo player. Synergistic TEs on non-eligible
Ghosts count towards the synergy bonus on the
eligible Ghosts. E.g., if someone solos the
dungeon with 10 CHARMS OF AVARICE, only five
Ghosts get TREASURE CHIPS, but the COA bonus
for those five Ghosts is at its max.
Example 2: The party consists of five real players
and five Ghost players. In this case, all 10
characters can have a number entered into Total
Treasure on the Party Card.