I did it! Wired up a ghetto bench harness with alligator clips and it flashed successfully in bootmode. I couldn't get MPPS to read or write in normal mode on bench though, "conditions not met".
Anyways, car works now with no DTCs.
For my own satisfaction, I still want to know why bootmode in the car was unsuccessful. I have no other ideas apart from too low voltage (my baterry was kinda flat) or noise on the Kline from other modules interfering with the bootmode flashing process.
I'd also like to know how to patch the NLS code successfully, but I know it's frowned upon here