"Programming... internal oscillator and internal MCLR... not supported..." / PIC12F1840

MPLAB X 5.00 + PicKit 3
Choosing DEBUG --> "Programming this device with both internal oscillator and internal MCLR selected is not supported."
 
There are a number of threads here on this issue. I gather there is no issue provided the pin is not used as an output - and for this device, section #12.2 tells you this is simply not possible:

12.2 PORTA Registers //DS41441B-page 113
Clearing a TRISA bit (= 0) will make the
corresponding PORTA pin an output (i.e., enables
output driver and puts the contents of the output latch
on the selected pin). The exception is RA3, which is
input only and its TRIS bit will always read as ‘1’.

 
-->Presumably this warning should not appear for devices where this is true?
 
 My desired config is this
#pragma config MCLRE    =  OFF      //MCLR/VPP pin function is digital input
 
Note: Following advice on this forum I have ensured that PicKit 3 | Program Options is 
"Apply Vpp before Vdd (Recommended)" because I'm currently trying to program with power from the PicKit 3.