Active Calories in Activity App are unreliable

For several years, I have tried to maintain both daily and weekly active calorie counts to a relatively high level (750 active calories/day). However, if the counts are inaccurate, I can easily miss my targets or over-exert. I have found active calories so inaccurate that I need to do manual calculations most weeks, ignoring realtime readouts on the watch.

Of course, I have contacted Apple support in the past but have gotten pathetic platitudes galore, stuck in the Infinity Loop.

The problems generally are:

(1). Inaccurate book keeping of cumulative active calories against daily active calories. The cumulative weekly total gets stuck at some value, while the daily active calories keep going up as I workout. Apple support, most unhelpful, asks me to restart the watch and the phone to make it accurate. That is just a lame workaround and not taking ownership of the advertised product features.

(2) Inaccurate count of active calories during a workout. Because the watch takes heart rate measurement at a relatively slow sample rate (minutes), it can miss large changes to heart rate during intense exercise intervals. A chest strap with Polar A10 gives a far more accurate heart rate at sample rates of seconds. Even when I setup Health App to allow Polar strap to overwrite Apple's poorly sampled workouts, the actual recorded Active calories remain unreliable. Only by manually checking and then keeping a separate journal of the difference can I get accurate values.

Apple Intelligence notwithstanding, Apple bugs need to get fixed on a timely basis to ameliorate natural stupidity. Any suggestions, if that is even possible?

I do have a paid Apple Developer status and can burn a support ticket if there is a good chance of resolution. Any experience with this type of problem would be helpful.