Solar charge controller coupled to power converter question

I have also thought about using a solar PWM charge controller and to use a DC power supply to replace the solar panel inputs. I found this discussion about why it is not generally feasible:

http://forum.solar-electric.com/discussion/22364/using-a-16vdc-power-supply-with-a-pwm-charge-controller

and this discussion:

https://www.solarpaneltalk.com/forum/off-grid-solar/off-grid-solar-panel-systems/21279-feed-pwm-charge-controller-from-dc-power-supply

Ed