Add a series resistor (1-10 Ohms) with the boost to slow down switch transition

Consider changing inductor to 44 uH, which will allow buck to operate in CCM mode at ~30 mA (at Fswitch=1.1 MHz).

Existing supply only recommends up to 10 uH, due to internal comp components.

If we switch to the AP63200, Fswitch changes to 500 kHz, and so L changes to 88 uH.  
This is much better.

New supply needs to handle 290 mA continuous load with external screen.  Without Nextion, power is 190 mA.

Tested existing supply with 68 uH supply... it was really unstable, and noisier under load.  Due to unadjustable compensation network.

Probably just leave existing power supply as-is, unless there's still too much noise after fixing the HVDCDC supply.

Solution:
Leave as-is

...
Verified fixed on RevB