OBS Base (Canvas) & Output (Scaled) Resolution Comparison 1440p & 720p
UPDATE: You can set the downscale filter to bilinear to achieve the same effect as when using both canvas and output 720p.
If you want to output 720p video using a 1440p monitor, just use both 720p for base canvas and output scaled resolution.
The raw footages are 24 second with 29.6MB (1440p base canvas & 720p output) and 19.2MB (720p base canvas & 720p output).
I recorded the footage using NVENC with CQP 18 with 1440p in-game resolution. And edit the footage with Shotcut and export it using CRF 15 using medium preset in 1440p.
I used a bicubic filter for the 1440p base and 720p output. If you use bilinear (downscale filter) in your "mismatch" base and output resolution setting, you could have a similar quality as using both resolutions (base & output) in 720p.