Baking and boiling eggs t'ain't the same thing

The eggs require a certain temperature for a certain period of time (I bring mine to the boil, e.g., bring them past 200F, simmer them for 1 minute, then turn off the heat and let them sit for 17 minutes... then cool them...voila, perfect hard boiled eggs, but then the rising doesn't matter...).

Yeast does most of the rising outside the oven. No diff, right, as high-temperature-trigger of rising is not a big part of the picture.

Baking Soda and an acid (buttermilk, lemon juice, whatever) reacts pretty well right away and continuously I think which is why muffin and pancake batter has to go in the oven right away -- again, should be no diff re altititude for such quickbreads. Mostly the same for the baking powder, the moisture activates the built in acid and soda combination, though SOME further rising occurs with both Baking Soda and Baking Powder in the oven.

Methinks, for baking, it's the air pressure thing more than the temperature thing, so it may be that your stuff is rising too soon and too fast with the lack of air pressure, then falling. Seem reasonable?

If it's any comfort, most people have considerable difficulty and must experiment with low-carb baking. Either a lack of gluten or conversely too much gluten is what usually makes low-carb baking so dang difficult.

By the way, you didn't say if you usually got bricks with ANY baking or specifically with low-carb baking?