I am learning that with everything leather making, there are no absolutes haha. Right from the leather used there have to be tolerances that can be allows for. So far I ground down and polished the centre foot for a smooth bottom and no indent from the groove, lower tension spring for the presser foot shaft, and also polished the edges of the walking feet. Rounded the throat plate edges and taped the corner too. My next task is trying out your plate and also a stirrup plate is on order for trying to get into gussets. Mainly simple seam but also lap seam is nice on the front which just doesn’t work well on the flat throat plate. It’s been a journey but I’m almost there! Haha.