Is there any way to manually invoke InertiaTensor calculation?

So I have a rocket with a rigidbody and a lot of parts and colliders. When rocket flies it consumes fuel from different fuel tanks each frame. Fuel have mass, so the mass of rocket constantly decreases. To speed things up I manually calculate rocket mass and center of mass. But I've notced, that every time I set mass or center of mass for rigidbody, it automatically recalculates intertia tensor which takes a considerable amount of time for large crafts. I can disable automatic intertia tensor recalculation, but then I need to calculate it myself, which I don't want to do. I want to invoke this operation only once, after I set mass and centerOfMass manually. Is there any way to do it?

ResetInertiaTensor doesn't look like what I needed, because it enables automatic updates after that.

I'm not 100%, but I think if you let Unity calculate it automatically, read it, then set it via
rb.inertiaTensor = whatever, it'll stick with the value you set.
Will you then need to scale the inertia tensor down or something as you lose fuel mass?

Interta tensor depends on center of mass which is constantly changing on fuel consumption. And I have some engines that consume a lot of fuel, so the changes to center of mass are very noticable.

I can write something like this:

body.ResetIntertiaTensor();
body.inertiaTensor = body.intertiaTensor;

after I set mass and center of mass, but it doesn't feel right. Also it would be great if Unity would be more transparent in the documentation on what is going on under the hood, when we invoke some properties or methods. It is not great when properties have such unknown side effects.

Ah, in fact as of Unity 2022 (I'm still using 2021) you have this as well:
https://docs.unity3d.com/ScriptReference/Rigidbody-automaticInertiaTensor.html
So explicitly setting that false after body.ResetInertiaTensor() is what you want, I think.

For some reason if i set this flag to false after invoking ResetIntertiaTensor() it resets intertia tensor to (1, 1, 1). So, I'll stick to explicitly assigning intertiaTensor for now. But I still think that side effects on every invoke of mass= and centerOfMass= was a bad decision because in cases when you invoke both methods, you'll do the work twice which is unnecessary.