Scart newbie help

[jimbobber]

Hi all!
I have a Raspberry Pi4 and use retropi and I love it!
I have a Pi2Scart adapter and while it works I have some questions.
OK, so first up - The resolution seems a little off, like it is not 1 to 1 pixel wise somehow, it's slightly off.
I am unsure what to do about this.
The Pi2Scart people say to add this:

disable_audio_dither=1
dtparam=audio=on
dtoverlay=vga666
enable_dpi_lcd=1
display_default_lcd=1
dpi_group=2
dpi_mode=87
hdmi_timings=320 1 16 30 34 240 1 2 3 22 0 0 0 60 0 6400000 1 #240p

into my config file, which I have done.
However, I do not know if they want me to ADD this to the config file (which I have done) or REPLACE the info with this?

My CRT is a Bang & Olufsen MX4000 if that helps?

The other things is every game, every emulator has a microstutter going on, no games are smooth - My test game is usually Sonic 1 on Megadrive and this does it too

Any help with that would be amazing!

Thanks