Anyone reading this thread fresh needs to be aware that if you are planning to use the Geeek PSU in a smaller case like the K39/Velka 3, that this particular modded 7660B is unlikely to be suitable. In something like the Metalfish S3, it's
only just compatible due to the case being a little bit larger.
You can see below that the modular PCB is mounted to the end of the PSU, meaning the cables come out horizontal. This adds quite a lot of extra length, taking into account the connectors, and cable bunching:
Even on the Metalfish S3, it's a very tight fit, due to the internal structure of the chassis. There's a lot of vertical structure in there that impedes the cable connections. You have to work it carefully a little with some of the cables pre-attached in order to get it to fit: