"Non-exclusive jurisdiction" clauses are put in because of problems with enforcement of foreign court judgments. If you sue someone in your country and win, but he has no assets in your country, you have to go to his country and convince a court there to enforce your country's judgment if you want to get your hands on any of his money.
Contract law differs a lot between countries, but any judge anywhere whom you ask to recognise a foreign court judgment wants to know at least three things: #1: the court which issued the original judgment actually has jurisdiction. #2: there's no more avenues of appeal above that court. #3: you informed the other guy before you sued him. If you can prove any one of those three is untrue, then you derail the enforcement of the foreign judgment. The "non-exclusive jurisdiction" clause makes it impossible to argue about #1.
Signing a contract for "non-exclusive jurisdiction" in HK doesn't restrict you or HKCorp trying to sue each other anywhere in the world you can convince a judge to listen. But it does mean that if HKCorp sues you in HK, wins, and then comes to your country to collect, you can't argue that the HK court was not a proper venue. While if you sue HKCorp in your country, win, and go to HK to try to get the judgment recognised, the HK judge will want to know why you didn't just sue in HK.