Um ... hello there.
I want to start by saying that I really like those mods of yours, specifically the auto-chest one and to some degree the dart one (that is to say, I like both of them, but I have a very nice bow now and a bajilion of adequate arrows so I didn't really get a chance to actually try the dart one out yet). I don't have the pillar item one as with me getting to the lunar event from a fresh start will take a year, by the way, so that's why no comment about this one.
That said, a random question: is it possible to get junk items with the Aquatic Fauna Detainer if your fishing power is low enough? I'm asking because I'm having problems getting seaweed for more than one chest (even after deliberately fishing in a miniature pond, I got 5 of those total, which all went for the first chest, and I'm sitting at 80 cans and 50 shoes right now) and it would be kind of a waste to ... well, waste, 24 minutes of getting decent stuff if you actually can't, so I'd rather ask on the off-chance that you remember.
On another note, it's ... well, not really a complaint but I guess it still is, though it's more of a thought rant, but I think that certain chests are a bit too easy to craft for what they give. I mean, I was able to make a Herbal Greenhouse before seeing either a Fireblossom or a Moonglow (and before having any Blinkroot or Deathweed seeds), and the requirements for the Satanic Resource Manager are kind of meagre considering that the chests are supposed to be auto-gathering stuff for people who've already mastered those particular aspects and the materials for this one can be gotten (unless playing Hardcore) by doing ninja-suicide runs with a few buckets of water and a hellevator as you only need 90 Hellstone (not hard, nor even takes a long time, if you just bunker yourself, concentrate on digging, and accept that you will probably die when the bone worm spawns) and 2 guide voodoo dolls (run away from Demons, only fight Voodoo Demons) and afterwards you will have all the Hellstone you can get. I don't know, maybe I just got used to the expert mode being ridiculous (I'm playing with both enemy modifier mods), but ... well, I can guess that for a person who doesn't know what they are doing getting those 480 clay pieces for the herb chest is hard enough that they will get all the herbs before that so it's probably me being an outlier, and other people might have a somewhat easier time surviving in the underworld due to the fact that I never smashed a single Shadow Orb or Crimson Heart ever (yay for skipping tiers) and my first fight against the eater of worlds was just me killing a few pieces to get the Shadow Scales for a pickaxe and then escaping before I die (again, yay for skipping tiers) so it may again be just me being an outlier. I mean, sure, the herb chest requires 5 diamonds, so that is something, but with the Regolith Gatherer and an Extractinator that's a complete non-issue, and the Jungle Rose ... well, it's more up to luck and patience than any herb-related resource gathering.
What I meant with all that rambling is that the underworld chest would probably be more balanced if it required an enemy banner of some sorts from there (Fire Bat would be good, those things are plentiful so anyone who actually survives in the underworld well enough to stay there and fight would have one). Likewise, though I like the Jungle Rose as a material for making the herb chest because I always go out of my way to get those things for myself (because it's the earliest-accessible head vanity item that shows the hairstyle, and it also looks good), I feel that due to its random nature it might be something that some less lucky people have to go out of their way to grind, sometimes for probably too long for anyone's liking, and it might be better if instead of that you crafted a seed packet with whatever amount of each seed type (5 would probably be good, though I can see it being more) and used that instead. I am not forcing you to do any of those things, mind you, I'm just rambling after probably spending a bit too long playing Terraria.