I have no clue whether or not you will answer since it is not a MOMUNIOUS claim but…
when the chavas daas disagrees (or is more machmir) with pri megodim or vice versa
when chavas dissgrees (or is more machmir) with sidrei tahara or vice versa
how does one paaskan in practice
is ther a maasorah?
I don’t know what “momunious” means, but there is no clear cut answer to this question.
The Peri Megadim and the Chavas Daas are both highly authoritative authorities, and each dispute has to be weighed up by the merits of each side, the proofs from Rishonim, and the tradition (mesores) of how later authorities ruled in practice.