I have a 4 in 1 iflight esc currently connected to my motors. I am attempting to interface it with my flight controller (Pixhawk 4), which comes with a power module (https://docs.px4.io/master/en/power_module/holybro_pm07_pixhawk4_power_module.html) in order to provide power to my escs and flight controller. This module has individual power outputs for every motor (each output is supposed to connect to a single esc, while the 4 in 1 esc only has one power input. Could I provide power to the motors by wiring all of the positive outputs together of the power module, and using them as the input to the esc, or would this create issues beyond losing the ability to track the power going to each motor? I am using a quadcopter. Thanks.
I think yes, this is doable. In this diagram you can replace the ESC Motor 1 with your 4 in 1 iflight ESC. Note that you will probably need to redirect the PWM outputs to your 4 in 1 ESC signal inputs.
Could I provide power to the motors by wiring all of the positive outputs together of the power module
No, no need to do that. Use a single power output of the power board (it is simpler and in certain cases more reliable).
Following the discussion in comments, your 4 in 1 ESC already acts as a power distribution board. Depending on your situation, you may not need the power module at all. For example, one could split battery power output into two: one to go directly to 4 in 1 ESC, and another one to an UBEC to get 5V (to power the flight controller).