MC34063 - Stucks with too much parallel devices
I have produced several hundred thousand products using MC34063 or equivalent.
I am "familiar with its operation."
However, YOU have not given us enough information for us to be sure what your problem is. 

The biggest problem is approximately what you say BUT from "the tone of voice" that comes across it sounds as though you think this is the "fault" of the people answering the questions :-) :-(. I and many others (not all) are eager to help BUT if people who ask questions decide to defend their approach rather than trying to help the people trying to help them it generally leads to worse outcomes than otherwise. 

People ASKING QUESTIONS are not expected to provide copious amounts of trivia, BUT it is common, as in this case, for those who ask to not provide data which is available to them and clearly relevant. eg 


You have not said what power you wish to provide per load device, or how many load devices you wish to drive  - these are utterly crucial factors and you cannot hope to design a circuit without such information. Neither can we. 
You have NOT said what the supply CAN provide at 24V - only what
(apparently) it DOES supply in this case. 
I suggested that you
short R26 - have you done so? 
What is the current rating of your 220 uH inductor. 
Please provide brand model datasheet link. 
Your timing capacitor on pin 3 / Tc is VERY small for this IC.
It puts Osc_freq at the top end of its range at around 100 kHz.
Why? 
What frequency do you see? 
What ton and toff. 
At 24V in and 5v out your toff needs to be about 5 x
ton. This may be a problem. 


Others have asked questions.
You have answered some.
You originally said 30 uA and now say 30 mA and,
we still do not know what current the supply can supply before it
current limits at 24V. 

Help us help you if you want help.