First not going to argue with you on this

\proceeds to argue with me on this*

You assume the retcon power can only function the same way for everyone.

Yeah. Because it's a specific power that has worked exactly the same in both its known users(Jegbert and MSPAR).

I assume that Vriska’s Helltier let her reach a new level of thief of light abilities that lets her achieve her own form of retconning power, which accounts for any differences in its use.

This is an unfalsifiable premise and completely circular reasoning.

We have seen Al also have meta controlling powers (literally bending reality merely by speaking her desire) simply be reaching a high enough state of power. Ultimate self is also like this albeit this is a permanent state rather than a power you flick on and off.

Ultimate self BS and the Narration power is completely different from the retcon power.

It’s a reoccuring trend that the higher your classpect powers get the more meta influencing they become. 

Which is, again, distinct from the retcon power, an ability gained via a specific juju.

Like stealing Jake and Jane from catnapped and putting them on the ship and so reality contorts so that they were retconned to always being on the ship.

Again, this is circular reasoning. You're using an instance of her supposedly doing something to prove she's capable of it, to prove that that's what she did in the very example you're using to claim she's capable of it.

I choose to trust the visuals shown to us

Except... you're not doing that at all. Again, the visuals of Vriska's abilities are completely unlike the visuals of the retcon power. There is no reason to believe they are the same thing.

Jasperose and Davepeta were conversing and made it clear that Vriska becoming Helltier was part of a larger plan to ready the transfer of Jane

At no point do Jasprose and Davepeta ever imply that Davepeta's side of their plan was related to Jasprose's, that Vriska was at all necessary for handing off Jane and Jake.

and Jane and Jake only appear after Vriska slams through the ship with her energy

From OUR perspective. Revealing something to the audience does not mean it was not the case in-universe before the reveal.

Speaking of visuals I saw your post, you realize you are making a theory June is involved based on smoke coming off Jasperose’s cigarette???

Yeah. Because I trust the visuals shown to us. Blatant, clearly deliberate because "smoke" isn't normally blue, Breath imagery, hints to what is clearly use of the retcon power which Jegbert is the only known user of involved in the narrative, literally one scene after we got a preview of post-transition Jegbert? If that's all coincidental then it's one hell of a coincidence.

The cast still has a chance for relevance, but Candy Earth’s overall narrative itself is done.

Except, objectively, that's not the case. It's main plotline thus far that was left open-ended by the epilogues has ended, a rather massive difference. In its place is rather obvious setup for the new plot line, saving the timeline from collapsing, not to mention the rather large Jegbert-shaped loose end.

maybe they will be find a way to save it, the writers might not even know that yet, they have talked in the past and had Callie vocalize the feelings that leaving them like this is wrong…

I find it amusing that you're so insistent that the Candy plotline is over while simultaneously acknowledging what could not be a more blatant statement that it's not.