From what you wrote above, it seems that you still don’t get it. “Should” is used in TWO different ways in English. You appear to be stuck on the one that means “ought to”. The subjunctive “should” does NOT mean “ought to.” Your sentence, “I should go to church next Sunday” means I ought to go to church next Sunday. That is NOT a subjunctive. However, if the sentence were:
“My wife pressured be so that I should go to church next Sunday,” THAT would be a subjunctive. I have already suggested that if you prefer, you can substitute “would” since that is the way many modern people used the subjunctive. The would say it this way:
“My wife pressured me so that I would go to church next Sunday.” That would the most usual way of using the subjunctive in our day. The meaning is the same whether the word is “should” or “would.”
This sentence DOES NOT MEAN “My wife pressured me so that I OUGHT TO go to church next Sunday.” Nor would it be appropriate to remove the first part and write, "“I will go to church next Sunday.” That would be a simple future and not a subjunctive at all. It would be true whether my wife pressured me or not.
So examining the Philippians passage, let’s substitute “would” for “should” and see if that makes sense to you:
So God exalted His Son and bestowed on Him the highest name FOR A PURPOSE. The purpose was so than every knee would bow to Him.
If we can accept that God’s exaltation of His Son will truly have this effect, then it will be true that every knee will bow.
By using “should” instead of “would” as the subjunctive, the meaning is the same.