[spirited irish]

Your premise slightly restated:

It seems Kant was fixated on the fact that natural science has a million and one useful applications while their supernatural explanations for physical phenomena have never been of any use to anyone.

Poor deluded fool. His “fixation” cost him his soul...and reason.

[allmendream]

So only by supposing that supernatural forces are accountable for physical phenomena can our souls be saved and our minds be subject to reason- despite such a premise being of no practical use to anyone ever?

That may be dogma among the fanatics, but it isn't usually Christian dogma among the vast majority of denominations that see no conflict at all between evidence and reason and Scripture.