CPU load concern with adding 1024...
Since there's no real estate for an additional checkbox, suggestion:
Have the 512, 1024, 2048, and 4096 buttons toggleable by clicking on them again.
Example:
Click 512 once, and it is 512. Click it again, it becomes edit: 1536. Click it again, it goes back to 512.
For 4096, this would be once = 4096, twice = 5120, three times = 4096.
Rationale: Not all of us hear much of any change, good or bad, with these minor changes, but do notice CPU load increases. Without being able to toggle, users that hear no change, and thus derive no benefit from the change, will be forced to have a CPU load increase, or decrease samples to 3072.
Edit: Not sure why my brain didn't add 1024 to 512 properly...
