What CMs to mix?

[Hanna]

This is probably a stupid question but...
Thinking about using one of the breathing ones plus a math problem or some stressful thoughts. Just wondering if they can only mix with the "exhale slower than inhale" one, as the other two (blocking and breath slowly before the next question) seems to slow/calm you down..?

[George W. Maschke]

I know of no reason not to combine mental countermeasures, such as rapidly solving a math problem, with any of the scoreable breathing reactions.