Right pretty sure I've finished the actual initial build and mod now.
Power supply now securely mounted vertically on the back of a strut, made a couple of minimal brackets.
It's got polyflex feet and a strut mounted filament holder and a shiny name tag made from aluminium filament.

The extruder is as optimal as I can make it with guide tube as short as it's practical to make it.
I've got the end stop screws within a couple hundredths of a mil of each other, I've set up a simplify3d profile and run filamentless prints for a few hours.

The only issue is the hot end side of the process. It simply won't print for more than a few minutes without jamming. And it creates a little bob of plastic at the end of the filament that will not fit back through the tube, so unloading is a real pita.

It's like there is a little chamber in the heat block that form a pool of melted filament that just clog everything up.

The filament just doesn't feed through to the nozzle cleanly or - as far as I can work out - in a narrow feed tube.
Whether or I can somehow fita ptfe guide tube in there I don't now.

Until I can extrude reliably, I haven't bothered facing the enormously complicated delta calibration process.

So whiole I'm happy with the kit and the instruction video/s. A 3d printer that won't extrude, is pretty pointless.