I am in process of internal testing on a completed companion called Malia. I assumed Storyteller was part of that mod as well so now I'm confused which mod he came from.
In fact, I haven't gotten far yet with many of the custom quest mods I've installed since I'm still focused on the vanilla story and dlcs. I haven't gotten far with many of the Interesting Npcs in that mod, although I've met quite a few while exploring. Oh, I've played the heck out of TftC, and can confirm that there's no "Storyteller" companion in it. And, with an add-on file, they even have dialogue for Automatron, Nuka World and Far Harbour. Their voice-acting is off the charts superb and their, very extensive, dialogue is funny, smart and varied.
Heather Casdin's a very close 3rd but, yeah, I can't say enough about those 2. Since you play with Tales from the Commonwealth, I'm quite surprised you didn't include R4-04 and Audrey (and even Birdie, although I haven't traveled with him much so don't put him in the same class as the other 2). Who are your custom companions/what are your recommendations? I have several installed but I've yet to start those quests so I'll probably add more of them as I encounter them. There may be some more custom companions from quest mods.
Synth06 - fully voice acted, also has her own quest/affinity/romance/worldspace/custom armor, and yes, a new pair of synth eyes.Randompanser - fully voice acted, has her own quest/affinity/romance/worldspace/custom armor.Wastelander Barb and Shei Wolf Ally - both are independent of the vanilla system (like Heather) and don't take up a companion slot managed by MCM as well.I'm assuming it's from Atomic Radio/Tales from the Commonwealth also would like to add The Wasteland Codex as a fun addition to the game, with all entries voiced by Storyteller himself. (4) The Storyteller - from New Vegas/Youtube fame another welcome addition as a companion due to his narration/voice acting strangely enough, I don't recall which mod I had that got him installed. (3) Mollie the Cheerleader - Made by vault75 I find this mod quite hilarious due to how much of a dumb bimbo Mollie can be when she talks the voice acting and quips are very fun to hear in the game.
Voiced by Potasticpanda (you may know her as Recorder/Ambriel from Skyrim as well as mXr's special ladyfriend). Has her own affinity/romance/perk, and her own quest, with a very disturbing twist. (2) Ellen the Cartographer - Another companion that's also amazingly done made by u/guicool138. It's an amazing companion mod that totally beats out anything Bethesda has come up with. She just feels smarter than any vanilla companion, more complete even. Is even a vendor with her own type of items. Independent of the vanilla follower system. (1) Heather Casdin - What else can be said about this mod? Perfect. Note that I won't be listing down any mods that just change a vanilla companion's appearance just the ones that add actual new companions. That being said, here are some companion mods I'm using for my playthrough. It has all the essential functions of several other mods, and even adds its own take on settlement building, outfit saving, dialogue, and yes, even a means for you to 'immersively' revive your own spouse. I'm using Amazing Follower Tweaks which is easily the best companion management/controller/overhaul mod in the game.