If you are running other mods that adds weapons which also use the SniperStandardFire ability, RPGO will most likely overwrite them to cost 1 AP as well.

If you think they should cost 2AP just like the ABBA weapons, you can leverage Iridar's Template Master to configure this in XComTemplateEditor.ini.

Here is an example of how I did it for the Auto-Sniper Rifle from ABBA:

This example ini configuration updates the conventional (ballistic) Auto-Sniper Rifle added by ABBA.

Note that this is replacing SniperStandardFire with a custom HanterRevertSniperStandardFire ability which I created for this mod, so you'll need to have this mod running if you want to make these changes to weapons from other mods.

Also, if there are any abilities or effects that specifically require SniperStandardFire, they may not work. I'm not sure if that's how abilities or effects work, but just a heads up.