What’s the power budget for the 3.3V power output pins on the GPIO header?
The TF slot, flash, 1.8V reg, rockchip, FE Phy, and Wifi are all drawing from the VCC_IO regulator so how much power is left for off-board devices drawing from the header?
The SY8088 should provide upto 1A with 5V->3.3V around ~90% efficency at full load, but I suspect it’ll probably overheat with such a small package and little thermal contact to the PCB.