The new hardware shows up in the macOS System specification pages below with sorely needed capacity increase to just under 1Tb. This alone is worth a consideration, many older Macs suffer from painfully small storage options and 1Tb brings this up to a more modern standard.
The Transcend JetDrive 850 960GB NVMe SSD is full recognised by macOS Mojave, and apart from some swings and roundabouts then installing, everything works.
Transcend JetDrive Toolbox is a downloadable software that supports the Transcend JetDrive series of products.
It’s still on the first release version, and we found it slightly lacking and didn’t do much other than confirming the drive was installed. As previously stated, we installed the JetDrive Toolbox software and only used the default settings.