You need a needle-tip solder iron and study hands to solder in electrolytic capacitors. The bottom side might have space if it is not mounted behind a touchscreen display, like I do often. Use a fine 31 mil (0.031") diameter rosin core solder, 60/40 mix. No one cares if it is not RoHS compatible as it has lead in it.
It is only 5 volts so any small diameter can capacitor rated for 10 volts will do. Shop at DigiKey, Newark, or Mouser for electrolytic capacitors that are long of body but narrow in diameter. The blog about inrush is correct, so to fix it try 100 uF capacitors, 1 by the USB-C power connector (bottom of the board), and 1 by the extra USB ports where you find both 5 volts and ground pins. Two of them should absorb the surge caused by plugging in certain USB devices.
Be sure the main power supply is 5 volts 3 amps or more, with no extensions or spliters added to the power cable. The Pi can be power hungry when running programs. Also consider adding a battery backup as a hat for the Pi.
I am adding a photo as to where to place a single 100 uF 10 volt narrow body electrolytic capacitor. It can be hot-glued on top of the Pi logo without affecting the slow signals to the header. NO glue or touch U3, as it processes any imported video you plug in.