There are 2 new UI scaling options as of patch 3.2
150% and 200%. Those 2 have exactly the same effect. There is no size difference between them. I use a 2560x1440 monitor and the 150 options is too huge which led me to believe this feature is bugged and the 150 has the effect of 200 which was intended for 4K res thus the super huge UI. Please check it out.