Even if we go for an SMT based system, there will always be this fight about up and down-votes and how much SMT something is going to be worth. It is not going to solve this problem, but shift the problem away to a different "currency".

I do agree that the base concept of it has a higher cognitive load though, but, as I described in an above comment I believe that a lot of it can be solved on the UI level.
You could have a slider similar to the voting power slider which might be centered around the current value and give some indications of the median value of this particular user or community. I do think that most of these complexities can be easily adjusted on the frontend.

Reddit works fine with up and downvotes because actually people don't see who casted this vote and no money only visibility is involved. This makes their system inherently simpler. Imagine how toxic reddit could be if they actually displayed who up and downvoted your content, imagine how many toxic DMs you would get. That's why I think, even for an SMT, the concept of only "up or down" is not helpful.

Thus, my concept would remove the concept of down or up-votes from the system, yes, of course, someone can just put a ridiculous value. But if he doesn't, his vote will never turn to a "downvote" because this concept doesn't exist. If I vote 5$ on a 50$ post, maybe I am shifting the average a bit down, but at the same time I am guaranteeing the author a minimum value. If I don't vote 5$ on his post, and a whale votes with 0$, he might get 0$, but if enough people assess it with 5$, this will be much more difficult for this whale to counter. Thus, I am helping the author to guarantee this minimum.