When i was refering to bridge chips i was refering to Jmicron JMS578 Bridge Chip, sorry i was too tired to remember the model. I know that others generaly fail at that and shouldn't be attemptesld at all to not destroy the ssd. I saw people use that one to flash firmware on ssds.That's a bad Combination, you should really change that PSU ...
USB <--> SATA Adapters are usually NOT a great Idea and I personally would NOT do it.
I'm not saying they will not work, but it's a huge Risk IMHO to use them especially for Firmware Flashing. It would actually be better if it does NOT work at all, that Way you will NOT be tempted to attempt a Flashing from such a IMHO Risky Procedure.