Having successfully gotten a mostly functional firmware on the V1/STM32F103 MCU Mini, I moved on to supporting the STM32F070 processor. That's the one that drives the Monoprice Mini Delta, the later run Malyan M200V2, the Malyan M300/Monoprice Mini Pro (aka V3), and highly likely to be the same chip in the new CR-10 clones from Malyan.
I do not know about the SLA printers - if anyone owns one, I'd love to know fi the motion controller is a variant wired to galvos or not.
In enabling V2 support, I discovered some ugly hacks I'd done to to the build flags and unwound them, and in a few hours, had a working firmware that boots on V2 boards.
These are, as of yet, untested in printers.
Why? USB support. I'm waiting for the 1.5 release with its CDC virtual com port emulation, which allows you to hook the printer up via USB.
Regardless, it's time to begin the work of integrating the boards for a proper PR, and also, figuring out how to support the Malyan M100, which is theoretically a variant, but I have reports that the same firmware doesn't function there.
One note about V2 support:
Copying over the vector tables in STM32F070 variant init means that pre-main intializers which use interrupts are in trouble. The vectors aren't in place until variant Init, which is part of the main() function (for arduino folks, that's before setup()).
I don't know yet what I"m going to do (if anything) about this.