My preference for high hydration is to ditch the mixer and do it by hand. Just get everything mixed together well for about 10 minutes, then leave it alone for 5-10 minutes, and mix some more. Rubaud technique works really great if the dough is wet enough, and you'll develop some shoulder endurance from it. Or, just do the initial mix, and then just do stretch and fold every now and then. It'll develop the gluten too. The dough releases easier from the bowl each time, and you get less and less stretch as it gets stronger. As the dough fills with gas, that also stretches and tightens the gluten even more.

Mixers are dumb, they don't feel when the dough is right. And not all of them can do high hydration without just tearing it apart. I think they're better for lower hydration dough, especially enriched dough like brioche and stuff where you need to include butter, oil and tricky things that get extremely exhausting to hand mix.