I don't think I've seen any suggestion thread for this yet, so going to throw it out here myself.
TL;DR: Make the wolf selection screens easier (read: Possible) to use; make the order make sense!
The wolf orders in the various screens to select them are all different!
The current wolf order when selecting in the Flea Market or the Specialty Item Selection screens is some weird logic where it takes the first wolf in your first den, then the first wolf in your second den, then first wolf in third den, then the second wolf in first den... but also sometimes skips them? it is extremely difficult (read: impossible) to organize your dens in any way to be able to easily list on the flea market or apply specialty items.
Whereas we have the breeding screen and the PM screen are in alphabetical order (ok, but not great - at least its able to be manipulated, if in an annoying way)
and then the hunting screen which is by den and in order! this I think is the best option of them all. (edit to add: also the campaign selection screen)
So basically my suggestion is: can we make this consistent and also be able to manipulate it so we can organize our dens in a way that we can list stuff on the FM, send trades, breed, use items, etc. more easily. As someone with almost 400 wolves, it is extremely difficult and tedious to get to the wolves I'm trying to sell. I can't organize my den in a way to allow me to easily list them, i just have to keep clicking through and hope I remember which of my wolves I wanted to sell.
In addition to this, I think the wolves that are available in the PM/Breeding/FM screens should be limited to those that can actually interact with that screen. (i.e., if i have a companion/apparel on a wolf, don't show it in the PM/FM screens - if the wolf is on cooldown, don't show it in the breeding screen). This would honestly be enough to make the FM useable for me, because I can put companions/apparel on the wolves I want to keep, and then only the wolves that show up (i.e., those that do not have companions or apparel) are the ones I want to actually list.
Edit to add: I am now up to 434 wolves, and trying to list on the FM is such a chore that I literally can't even get rid of them. I don't understand the organization system for this, i can't jump to different pages, I have to literally click through 40+ pages one by one even if I know what page I need. It's just unwieldy and frankly ridiculous lol