Manual control IR cut filter

I bought the IMX219 camera module with motorized IR cut filter (B0154). I intend to use it on a Raspberry Pi 3 (or Raspberry Pi Zero 2 W). According to the the following article the IR cut filter can be controlled manually:

But the documentation, mentions that the photoresistor should be removed and weld a 470 ohm resistor:

Removing the photoresistor won’t be a problem, but how do I weld that resistor? That connector looks just too tiny to solder anything?

Is that resistor really necessary? It doesn’t seem to be needed for the Raspberry Pi 4, so I wonder if I can also control the IR cut with a gpio, like is explained in the Raspberry Pi 4 instructions.

What’s the purpose of that 470 ohm resistor? Can I control the IR cut manually without it?