I've been working on my own regulator based on the advice I've received here to ditch my lm338 idea.
I came up with this, It's rough, and I'm sure there's some mistakes, but if someone could throw some ideas my way it'd be great. is my theory and application okay for the analog circuitry for the most part? I gathered some inspiration from watching Dave and Gerry Sweeney's videos on their lab power supplys. I'll replace the main pass transistor with 1 or 2 darlington power transistors.
As for what I want to achieve with this project-
I have a couple of low-current 20-30 v maximum power supplys that I use for my projects. I built them over the years, and they're used to power anything from MCU's and such, all the way to fully analog circuitry and tubes etc.
Ultimately my intention for this power supply project is to get a small compact fan cooled supply with a micro controller to give me flexibility in programming it. be that through serial, or buttons/rotary encoder as I'm putting on the panel. I want good clean power and I don't need high voltage, it'll be mainly for sub 12 v precision circuitry and I want a nice clean output at high amps. I really want to have a current limit that I can reliably protect my projects with too.
It will be compact, linear, and fully cc/cv controllable. I am shooting for 12-15 volts max, with 4 or 5 amps current capability. I'm going to get a nice chunky transformer (hopefully toroidal) to achieve that sort of output. I want to use 12 bit dacs so I can still have small steps with my output amperage. I want to use a constant current device like dave did so it can be calibrated out easily.
I will hopefully get this on a breadboard/stripboard before I move house, I will post my results here when I do.

Excuse my scratchy writing and schematic, it's much easier to think on paper when you can use an eraser much easier than on the PC.