I think you’re looking at voltage glitching with the ChipWhisperer crowbar circuit. If that’s your goal, you want the glitch output to be connected directly to the chip’s VCC pins - when you apply a glitch, you want to cut power to the chip as quickly as possible. If there are any decoupling capacitors nearby, then your glitch output will have to drain the charge out of them before the chip’s voltage actually drops.
Also, remember that you’re shorting out the power supply when you do this, so you can cause some pretty huge current spikes. The only passive component you might need is a resistor to limit this current. If you have a shunt resistor for power measurements already, then you shouldn’t need anything else.
Good idea to emulate the CW303 board - see if you can use the ChipWhisperer targets as a reference.