there's no point of correspondence with reality unless you declare one.

Well, it's called "subjective" for a reason. If we agree that no prior is privileged, why should anybody commit yourself to one? If different Bayesians can have completely unrelated priors, why cannot a single Bayesian have one for Wednesdays, and another for Fridays?

I tried some back of an envelope math to see if some middle way is possible like limiting priors to those weighted by Kolmogorov complexity, or having prior with some probability for "all hypotheses not considered" but all such attempts seem to lead nowhere.

Now if you think some priors are better than others you just introduced a pre-prior, and it's not obvious that a particular pre-prior should be privileged either.