I contacted Dolphin and asked them if connecting an external 12V supply to pins 1, 2 and 3 of the adaptor would enable it to work with the "big inductor" SSD. They said it wouldn't work.

Ace's adaptor is very clever. It uses pins 1 and 2 of the SATA power connector (these pins are "reserved" or unused) to control the SSD via I2C. When the SSD becomes unresponsive, Ace's Portable can toggle the SSD's hardware reset pin(s). I doubt that Dolphin's adaptor is able to do this, but a look inside the metal can would be very useful. Also, a photo of both sides of the m.2 adaptor would provide a lot of clues, too.

I think Ace's Portable might be able to control other devices via pins 1 and 2. I expect that the unit either has a dedicated I2C host controller, or perhaps Ace bitbangs a couple of GPIO pins to simulate an I2C port.

U1 is the 53rd and 55th pins that NB3N3002DTG connects to the M.2 interface, used as an external clock generator for PCIE host. U2 is TCA9534PWR, an 8-bit expansion chip from Texas Instruments that expands to 16 bits of I/O, used to distinguish whether the hard drive inserted into the interface is using SATA or NVME protocol. Power on/off control is handled by the P3 Portable host. As for determining whether SSDs are frozen, I think it should not be a hardware issue with the converter but rather a status register in either NVME or SATA protocol.

I have it. Let me know how i can help you.

Can you show us photos of the m.2 adaptor and a photo of the inside of the metal can?