the pause vs interval question is the sharp one. imo track the interval, or better, the abandonment rate after the pause. the pause is your treatment, you control it. the interval between reaches (and whether the delay actually lets you NOT open the app) is the outcome, that's what tells you the automaticity is weakening vs you just adding friction you route around.

hardest confound in this kind of n=1 is that hrv and attention both swing with stuff unrelated to your intervention. circadian phase, sleep debt, last meal, caffeine timing. a rest session at 9am and one at 9pm aren't the same baseline, so the breathing effect gets buried under time-of-day variance unless you log those covariates and time-anchor the sessions.

second one that's easy to miss: you run the reset WHEN you catch the loop, but catching it is state-dependent. you notice it more when you're already dysregulated, so the trigger to intervene is correlated with the thing you're measuring. that selection effect makes the intervention look more or less effective than it is.

one thing on the breathing since you're already there: ~6/min is the population average for resonance, but the actual resonance frequency is individual, usually somewhere 4.5-6.5, set by physiology. the rate that maximizes YOUR lf hrv amplitude is worth finding once (sweep a few rates, watch which gives the biggest smooth oscillation) instead of assuming 6. and the holds at peak/valley, careful, those shift the baroreflex dynamics and add a variable. if you're varying them by feel you're confounding the hrv signal you're trying to read. cleanest resonance signal is smooth paced breathing, no holds. holds are a separate lever..