When mirroring my Macbook Pro with an ultra-wide external display, can the resolution be set to the external's native resolution?
To emphasize again, this question is about mirroring. I'm looking at buying a 3440x1440 (or higher) resolution monitor, and I'd like to use it as the only display with my MBP while keeping the MBP open. From my research, it doesn't seem possible to do this. The workaround I found, was to mirror the displays. So, if I do that, will the resolution match the external display?
Yes. When mirroring, you can choose which display to "optimize" for.