Going backwards, can't even get a basic blinky working now

[Demon]

Regarding the overshoot issue, if your PICkit 4 is serial number BUR20xxxxxxx or later (-R2) then it has a mod in it to reduce the overshoot so it's not as much of a problem. Before that, they used to recommend using a 470R in series with the PK4 MCLR connection to the target.

From ETN37:

BUR223673449


Do you mean -R like a command line? Taken from the IPECMD docs:

R<on><off>

Safe/Restricted mode (Applicable only for MPLAB PM3)

Default = None

I'm running the PK4 from MCS+5.

Robert