I used Hall effect sensors for a project and found they needed a fair bit of calibration. Shunt resistors also did the job with fewer problems but this was a 16p2s module.
Hall sensors have a lot of issues. If you can handle the power dissipation in the resistor, a shunt plus a fancy zero-drift difference amplifier is almost always going to be superior.
Hall sensors win for very high currents, high bandwidths, and when isolation or noninvasive measurement is required.
Technically, yes. That's how most meters work. But now you have high current, high voltage, and isolation issues in your sensing device. So you need more testing and approvals.
From AliExpress?