I made a batch of 4 loaves using the new formula in a 6qt, 575 watt KA mixer. After reading experiences from other bakers, I made a few changes to the mixing process that seemed to help and I wanted to share
I added about 30g of olive oil to the oatmeal, reserving the remaining 50g and honey to add later.
I found my mixer struggled when I started with all the poolish and autolyse for a full batch. I ended up scooping out about 2 handfuls and continued mixing on the lowest setting. No dough creeping – yay! I increased the speed to 2, and added back in golf ball sizes pieces of the dough on the higher setting. I ended up repeating this process when I added in the yeast and salt. (Scoop out about 2 handfuls, add yeast, mix on lowest setting until mostly incorporated, increase speed to 2 and add back in small pieces of the remaining dough. Repeat with salt addition.)
As soon as the salt was incorporated, I drizzled in a little of the remaining oil. I notice the dough immediately dropped off the hook and began to form a cohesive ball in the bowl. The mixer also had a much easier time kneading the dough. Each time the dough started to creep, I drizzled in a little more oil until if fell off and let it run. I did a few windowplane tests to see how the dough was coming along. When I ran out of oil, I started to drizzle in the honey. By the time I was done adding both and they were fully incorporated, the gluten had developed to form a windowpane.
I added the porridge in small handfuls using the lowest setting. The dough still crept, but not as much as before. I found I could add in a handful, mix about 15 seconds, pull the dough down, and add more porridge. It took about 4 minutes to get all the porridge dumped in, but much less creep and everything was mixed in evenly.
I proceeded with the rest of the steps. They baked up beautifully. I think dropping the formula to a 3-loaf batch would work best, but it was useful to know that 4 loaves can be done if I use the oil and honey to help with the mixing stage instead of waiting to the end to add them in with the porridge.