This online source is confirming my stance that scientists had actually applied Newton’s Theorem XXXI to the Galactic Rotation Problem.
Above source is criticizing that scientists should not have modeled gravity of galaxy like that (i.e. like Theorem XXXI). However this source has not reached to the point of Theorem XXXIII.
My book Philosophy Unscrambles Dark Matter has pointed out that Scientists should have applied Newton’s Theorem XXXIII to galactic rotation problem but they had applied irrelevant Theorem XXXI which was applicable to solar system and that’s why scientists were wrongfully expecting “Keplerian drop-off” from galactic rotations.
Here is the free complete section of book that explains that actually applicable Theorem was XXXIII that naturally gives flat rotation curves for galaxies.