I have a tendency to sound superior or dismissive, so I apologize greatly if this post sounds that way. Especially since you have such great taste in gear. But it seems you could be greatly helped by a course in instrument setup and terminology.
"High neck tension" - that is, the pressure the truss rods are exerting on the neck - would result in too
low action (string height.) The strings you use do matter. Have you replaced the factory stock strings, or were they strung up with a new set? Does the action change during seasonal changes? If you're attempting to lower atrociously high action, you need to start with the neck, not the bridge.
There are many, many, many instrument setup guides on youtube, but there are just as many idiots offering bad advice. They all mean well, but some suffer from simple ignorance, while others cling to outdated ideas. If you want an A to Z guide to the mechanics, I highly - HIGHLY recommend picking up
The Bass Player Book. It starts with terminology, moves onto technique, then instrument setup, amp configuration, and tips & tricks from some of the worlds leading bass players. I recommend this book to most all players, because even though it starts with the basics, the writing is engaging and informative. Even for experienced bass players, it offers plenty of "d'oh, that seems so obvious in hindsight" moments right from the start. I really can't recommend this book enough.
Outside of that, your best bet is to cozy up to your friendly neighborhood luthier. If they're worth their salt they'll explain what's wrong, and how to fix it. I learned a lot just by bumming around my local guitar shop, asking questions. If they kick you out, then shag 'em. Learn the basics, and once you understand the fundamentals, you'll be amazed by how much you can accomplish on your own. Plus, it's a hell of an ego boost
