After many tav and durge playthroughs, I wanted to experience the Origin characters' content, but I didn't want to be locked into one character's story for the entire playthrough and miss out on hearing their voiced scenes. So I started toggling the Avatar tag on companion characters during my playthroughs.

Untested on nautiloid.

This mod adds an avatar passive that lets you toggle avatar tag on the six origin characters when they start the game as companion. This passive will not be automatically added to origin characters that start the game as avatar/player controlled.

You can manually add the avatar passive to any character in your party. Have the character selected then run this in your script extender console:

Osi.AddPassive(GetHostCharacter(), “MX_AVATAR_PASSIVE”)

The Avatar tag
The Avatar tag tells the game that the character is play-controlled. All tavs and durges already have this tag. Companion characters only have this tag if they are Origin characters (started the game as a player character). By setting this flag during a playthrough on existing Companion characters, a few changes occur in the character:

- The character can lead dialog and make choices for all regular scenes, like a tav can
- The character's Origin story will be used instead of their Companion story. This means they will experience the Origin versions of these scenes, where they will not be voiced but will make dialog decisions. This allows you to roleplay their personality as you want!
- Other companions will have character specific dialog for the character, just like when you're playing as durge.
- The character can gain approval, and romance other companions. You can also have reciprocal relationships (two companions romancing each other). Though they will need to have their relationship flags adjusted (relationship status and approval won't sync bidirectionally).



This mod is an implementation of how I play the game.
The Avatar toggle is a Passive on each of the companion characters. When enabled, the character will get a blue status indicating they are currently an Avatar. You can have as many or as few companions with the Avatar toggle on at a time! However, you will need to have one TRUE player character - a tav or durge, or a "true" Origin character. If you do use this mod on a save with a true Origin character, their Avatar tag will not be togglable and they will be treated like a tav. (A friend who helped me test says that tavs can be stuffed into Wither's Wardrobe but Durges can't, so you can try that if you absolutely don't want a tav.)

There are many other small implementation details in the mod to make this kind of playthrough more immersive, which I can talk about in comments. I also added a set of utility spells that gets added to companions that have the Avatar toggle enabled. These spells allow adjustments of approval and dating and partnered flags for easier roleplay (Note that the partnered spell does not set Halsin's SECONDARY romance, only primary).

In one of my playthroughs, I play my tav as Gale origin using Appearance Edit Enhanced mod to customize Gale to my tav. Playing with the Avatar toggle allows my tav and Astarion to have reciprocal romance using both Astarion and Gale's romance story at the same time. They can also talk to each other, and hearing my tav talk to the party and to their partner gives them way more personality.


The following characters can become Avatars and have Origin storylines:
Shadowheart
Laezel
Karlach
Astarion
Gale
Wyll

You will only find the Passive on these characters. It will be a blue passive in the right-most area of the hotbar (for easy access).


This mod is useful for roleplay.
It allows you to roleplay all the companions in the same playthrough, changing their personalities through the decisions that you make for them. The party will feel more like a "we" than you as tav vs the rest of them. Characters will develop more depth as they participate in the important decisions, and build different relationships with each other. For example, companions will have different approval with each other, which will affect how they talk to each other.


This mod is GREAT for making videos and taking screenshots of Origin content.
You will not need to play entire Origin playthroughs to see late-game Origin content. Just toggle the Avatar tag in your existing late-game saves and talk to companions to get Origin specific responses! For example, if you want to see Origin Astarion's Cazador scenes, just load up your regular save before the fight, toggle Astarion to Avatar, and then go to Cazador.


Gotchas!
I do not recommend using this mod on a playthrough (or at least, don't save) you care about because there is some gotchas to doing this. For example, you could miss parts of the story. However, you can always force these scenes through script extender commands or set flags that were missed (this is what I do, but you need to know what you missed). Here is a specific example:
- If you enable Astarion's Avatar tag in act 1, you will get the Origin version of the bite scene (where he has a nightmare). Then even if you toggle the Avatar tag off, he may not experience the companion version of the bite, and may be missing the companion knowsVampire flag, so party members may talk like they don't know he is a vampire yet.

It's not as a big deal if you don't toggle Avatar tags on and off like I do. Just know there could be issues!


----

I have no idea what to put for main screenshots so here's some images of Astarion talking as Avatar...

---

Mods used in pictures:

Appearance Edit Enhanced
Vessnelle's Hair Collection
Boring Dyes
NPC Dyes
New Eye Colours (and blindness for all eyes)
P4 bangs bangs
PK Clothes and Armors
Basket Full of Equipment
PK Clothes and Armours
ASTRL's glow eyes, hair and skin mods
Lord Astarion's Crown
Half-Tiefs
Horns of Faerun
Half Dragon
Alternative Horns for All

---

Thank you 
ShinyHobo for Multitool
Norbyte for ExportTool and Script Extender
LaughingLeader for ModManager
Moona for testing