What does `ARWorldTrackingTechnique: resource constraints [33]` mean?

We are building an ARKit application targeting iPhone Pro devices on iOS 26.4+. During testing, we consistently observe the following log message at a specific point in our AR session (approximately 90° into a walking arc around a vehicle):

ARWorldTrackingTechnique: resource constraints [33]

What specifically does resource constraint code [33] represent?

Is it a VIO constraint type, a sensor fusion budget limit, or something else entirely? How does it differ from code [1] (which appears to be a general CPU starvation signal for the ARKit sensor fusion thread)?

Is there a public API to detect or respond to this specific constraint condition, short of waiting for a full ARCamera.TrackingState downgrade?

Was this constraint type introduced or changed in iOS 26.4?

What does `ARWorldTrackingTechnique: resource constraints [33]` mean?
 
 
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