MTP sucks, it’s even slower than good WiFi and half the time it locks up in the middle of a transfer.

There are simple testers like this. It’s rather overpriced for what it is, but it would be trivial to make one yourself. That will only do a continuity check though. If you want to know what the current or speed ratings are, you will need to read the chip in the cable.

Timeshift works best if you use BTRFS for your root partition because snapshots can be taken instantly. I have mine setup to automatically take a snapshot every day.

The MOSFETs are in series, but in opposite polarities. Two MOSFETs are needed to block current in both directions.

The DW01 uses the voltage drop across the MOSFETS to measure the current. The overcurrent threshold voltage is fixed at 150mV. Using a larger MOSFET that has a lower RDS(on) will increase the current limit.

The drains in the 8205 MOSFET are connected together internally. In a DW01 circuit, they are not connected to anything else.
One MOSFET stops the battery from charging and the other stops it from discharging.

For something that’s not switching at a high frequency, slow rise and fall times are fine as long as you are staying within the safe operating area of your MOSFET. A 10K gate resistor could certainly work, but it will depend on your MOSFET and load.

I did that about 10 years ago because I got tired of removing malware for them. They haven’t had any malware since then.

MELF stands for Metal Electrode Leadless Face although anyone who has had the pleasure of working with them will tell you it stands for Most End up Lying on the Floor.