I have used the inner tracks quite a bit while I was racing in SF. No issues with the jib fouling or the strength of the track. Because of the length of the track, the load is spread out over a large area even without large backing plates. I don't see how additional plates would hurt though. When not racing, the small improvement in pointing isn't worth it.
And honestly, you likely need to improve your sail trim skills before using the inner track, as if you don't trim it correctly, you will lose pointing ability with it. Just something that I learned, both with trial and error, and some advanced sail trim study. With new sails I can point to 29 apparent on the outside track-with the correct trim. On the inner track, I found that I was losing more to leeway than I was gaining. I would "point" to 25-29, but the boat was moving close to 50 or 60.
It might be hard to visualize, but the jib needs both shape and some angle. If you ease the jib, the increased angle will provide a bit more forward lift, and a bit less sideways lift. So if you over trim, you have too much sideways and not enough forward, and get more leeway. And you should never trim the jib flat, that would produce no lift, only drag. So even on the inside track, you should never trim so tight that the jib touches the shrouds. This is where the adage "When in doubt, let it out" comes from. Also, the best trim is usually to easy the sail until it just barely luffs, then trim until it barely doesn't.
What the inside track does, is allow you to ease the sail more, so that the clew is in the same general position as if on the outside track, but with a lot more shape. You would really need to be paying attention to utilize it, and would probably be switching back and forth between tracks often.
If you are interested in maximizing your sailing, I highly recommend this book:
North U Performance Trim (landfallnavigation.com)