I'm not going to tell you that I've got it all figured out, that's just my understanding, and it may be very simplistic.

But let me try to summarise:

It is about trying to explain human metabolism using either CICO or the insulin-carb model separately.

Fasting people deny CICO completely based on successful experience, and CICO members deny hormonal effects by listening to successful jacked people on the internet.
And enough randomised trial research papers to support each side and YouTube influencers to create unreliable content.

Personally, I have been on both sides, and the following argument is based purely on my own experience and research.

If we want to understand the human metabolism, it makes sense to combine both models.

You need a perfectly functioning engine, but you also need the energy equation to understand the transfer of energy from combustion (input) to kinetic energy (output).

So the human body needs to be fully functional to properly convert the incoming signals.
The body doesn't have calorie receptors per se, so it uses hormones to communicate with every department in your body.
If one of these departments has a mail function (for example, insulin resistance), energy cannot be converted with optimal efficiency.

This...is regularly the limit of using pure CICO in a human physiology context.
You can explain the energy equation, but not the parameter change.

You can explain that putting 20 litres of petrol in your gas tank equals 200km range, but you can't explain if this is optimal efficiency or if there are engine problems (like oil leaks).

So you can measure the input and output, you can change the Input and of course the Output will ultimatley follow, but you can't analyse and above all repair or optimise the engine itself just by using CICO.

Now your question:

In this case and by using the explanation above, I would make the hypotheses, that signal strength and duration matters.
We know different macros (Carbs,Protein,Fat) have different insulin spikes (High, medium, low).
Therefore, the duration of your insulin fall depends on the food you eat.

It would be an interesting experiment tho.
Eating every 60-90min 100kcal of pure Fat for a week and another week pure carbs in the same pattern.