Power tree understanding
If you want locally_clean VDD, then use a LOCAL_BATTERY, which you make.
Use a 1 ohm resistor in the VDD, with 100uF shunt right at the  IC(s).
The 1 ohm is needed, to ensure other distant loads cannot suck charge from your (clean) 100uF capacitor.
And you need to Ground the 100uF directly to the GND pin of the IC.
You cannot replace the 1 ohm with a ferrite bead. FBs do not work at low frequencies.
The combination of 1 ohm and 100uF is 100uS time constant, which 1.6KHz low pass filter. No FB will do that.
You can used lumped inductors in place of the 1 ohm, if the DC_drop across 1 ohm is a problem.
Notice you are spending PCB area, and money, to achieve clean VDD and thus clean measurement. That is life.