Airflow methods in controlled residential ventilation all through door gaps?

That is negligible. You can install bypass valves or door seals with bypass capability. But you don't have to.

With controlled residential ventilation, you can neither cool nor heat.

Cooling coil in controlled residential ventilation?? Probably works if you know what you're doing
Condensate must be monitored.
Will be installed soon in my nephew's house (building services engineer)
In connection with LLWP, manufacturer / supplier of controlled residential ventilation (Helios) naturally says: without guarantee
I am of course curious whether it will turn out as expected and planned...

Of course it's possible. But it only makes sense if the air exchange is significantly above the standard. With the right planning and the right devices from Helios, it is also no (warranty) problem. However, this is already far from standard. For smaller houses, conventional air conditioners are better.

[...] in connection with air-to-air heat pump, [...] Of course, I am curious whether it will turn out as expected and planned...

If you imagine dry air, discomfort, and high heating costs, then it will surely be as planned.

Cooling coil in controlled residential ventilation?? It probably works if you know what you’re doing

That’s not what this is about at all. A typical controlled residential ventilation system is there to ensure the minimum air exchange, but not much more. The units are far too small for that.

Of course, with cooling and heating coils, as well as humidifiers and dehumidifiers and multiple heat exchangers, the air can be conditioned as desired. Cruise ships and hotels show how it’s done. But that is far from the “typical controlled residential ventilation” in a single-family house. Both in terms of cost and dimensions, and of course the air volumes moved.

You can also drive a 40-ton truck to the bakery. It probably works if you know what you’re doing. But that is not the usual approach and is not the subject of this thread.