Have you tried a harness with a third strap, like the Ruffwear Webmaster? There's others with this design, but that's the one I know has a good reputation. The third belly strap behind the ribs makes it much harder to back out of. If you want a lighter weight design, I know a lot of the escape-proof harnesses designed for greyhounds and other sighthounds also use the triple strap design, so if you can find someone making those in your pup's size they may be worth checking out.
Martingales are also very good for preventing lead slipping, but I personally wouldn't be super comfortable leaving a dog tied to a run with any collar, especially when she has a habit of fighting to get loose. But it's absolutely up to you - I can be on the anxious side and there's a lot of things I wouldn't risk that many people do all the time and are totally fine, haha, so take that for what you will!
Martingales are also very good for preventing lead slipping, but I personally wouldn't be super comfortable leaving a dog tied to a run with any collar, especially when she has a habit of fighting to get loose. But it's absolutely up to you - I can be on the anxious side and there's a lot of things I wouldn't risk that many people do all the time and are totally fine, haha, so take that for what you will!
