I'm really glad Klei added a pause mechanic to DST it really makes the game feel more refined and complete! Coupled with the 64-bit from the waterlogged update the game feels so much more on par with other survival games than it did years ago it's great!
Here's some QoL features I think would make the game feel even more refined and just make it higher quality!
1) Being able to play in your own world regardless of your internet connection! Right now if you make a world while offline you can never play online on it and if you make a world while online you can never play while it's offline, DST is the only survival game I've seen like this and that's because of its the skin stuff... it would be nice if we can play in our worlds whenever we want and being online or offline only effects whether you can play with your friends or not like how it's in basically every other survival game with multiplayer!
2) Make insanity ambient volume have its own separate volume setting! Insanity ambient sounds being tied with the actual ambience volume is very annoying which forces you too either be annoyed while insane (especially if I'm playing as a mod character which benefits from being insane!) or basically mute most of the game's audio so all you hear is your own footsteps most of the time... If a mod can do it, you can too, Klei!
3) Show mod characters on the world select save slots! DST has a very big modding community and I'd argue it has a huge impact on the game's popularity and strengthening its lifespan too! Anyways.. most of these mods are character mods by a huge majority, I mean who doesn't like a cool new character to play as! Mod characters can be really fun and creative new ways to play the game, there's just one thing that they always have been lacking compared to Wilson and his friends is that they don't show up on your worlds! If you guys can add a feature like this mod to make the "saveslot_portraits" actually be used or at least show their heads (floating heads lol?) on your saves you're playing as them it would be real nice! C'mon, Klei! Allow us to see our glorious mod characters on our saveslots without the need of a mod!
4) Mod presets like world presets! When you make new worlds very frequently and have a big list of mods it gets kind of annoying of going through a hundred mods to enable the 25 you want to use for this new world.. like the great world preset feature we got from a QoL update sometime ago it would be great to be able to do to same for mods then with the click of a button we can enable all the mods we want to 
!
5) Tooltips for setting options! There where times I sometimes even get confused what some options did exactly and I'm sure for every newcomer they feel like that for certain options for a long time cough..LagPrediction..cough it would be very helpful if all or at least the settings which aren't as straightforward in title would have tooltips explaining what they actually do when you hover over them. Then players can actually know what happens without having to do their own testing or ask on the forums or search a wikia.
6) Allow to choose your world seed when generating a world! Popular survival games like Minecraft and Terraria allows this and it allows sharing really cool and crazy worlds with other players then everyone can have fun with them! It would be great if we could do the same in DST too! There's a mod which even adds this feature... now all we need is for it to be a part of the game!
That's all the stuff that comes to my mind now! I think these QoL features would make the game just feel a lot more refined and awesome! I hope to see them overtime in other updates like other great QoL features that were added like 5+ world saves, improved world presets, improved mods menu, console auto-filling commands, opening containers at the same time as other players, 64-bit, pausing mechanic, and probably some I even forgot !