Try moving some weight forward. Bolt some lead to the steering support in the front and see if it helps your condition. With the seat in the stock position I’ve always found my 4S needs 5 lbs on the nose to handle well. Otherwise I’m running a similar setup to yours, but with a world formula. On new Burris 55s I’d have been around 54″ on the rear and narrow on the front, 5mm to 10mm of spacer.