I added support for PIC16F1454, 1455, 1459 and LF variants. I had PIC16F1455 at hand, so I tried to upload some small program and it worked as expected.
Some minor mistakes fixed for PIC12F18xx.
PIC12F1840, PIC16F1503, PIC16F1509 tested and working too.
PIC programmer sketch verified to run on 2USD chinese arduino nano clone with CH340 USB-serial converter.