The picture above is the ducts that are to the Bathroom and the vent just outside the bathroom door. SO much air coming out of both caused both those areas to get so much hotter than the rear living area. I removed the collars coming out of the furnace and blocked 1/2 the outlet with sheet metal.
The image above is of the mod going to the ducts in the living area. I used 4" aluminum 90º ells from Home depot. Installed them on the collars coming off the furnace. I removed about 6' of the scrunched up flex duct the factory installed. The smooth radius of the aluminum ells and stretching out the flex allowed for much more air discharge at the floor registers in the rear living area. Getting more airflow from the living area vents than from the bath and hall vents now. A friend has a air velocity meter, going to try and borrow it from him to know how much air flow I have. I ran the furnace thru several cycles, sure seems even.
No matter what I try to do my pictures come out 90º off, sorry about that.