Hello @Xayzer. Im new to blender along with python scripting (but have dabbled with other scripting languages and programing languages); based on @Zoot suggestion i put this together.
Ive only done a little testing on a small scene (just the default cube and three camers) so i have no idea how scalable this “add-on” is, but here you go.
Disclaimer: if your computer starts to dance around and do odd stuff, sorry, your using this at your own risk
Like suggested, name your camers with a suffix of (hyphen res) -1920x1080 and during render (f12) the script will change the resolution based on the name.
the render resolution will be 1920x1080
the render resolution will be 3840x2160
The add-on only works with still images, not animations.
You can use the timeline and set markers for changing cameras, but again, this add-on only works for still images and not animations. What ever active camera is set will effect the rendered resolution.
If this is what your looking for (and it works for your needs), any feed back is welcome and then ill probably start a new thread for it.
Post back any questions… have fun.