The schematic shows approximately Vce = 3.1V across Q109 and Q112. That calculates to 155mW for each transistor with 50mA flowing. The original transistors were rated for 320mW maximum.
I personally prefer running these parts cooler than the original design for better long term reliability that is why I’m proposing the bigger transistor packages.
I personally prefer running these parts cooler than the original design for better long term reliability that is why I’m proposing the bigger transistor packages.