Does Swiper's parent automatically block touch when a nested child Swiper is active?

Background

Swiper supports nested carousels via the nested option. When both parent and child Swipers have allowTouchMove enabled, the library’s event delegation may let the child consume a swipe, but the parent can still register a touchstart and trigger a slide change.

Uncertainty

The current documentation does not specify whether the parent automatically blocks touch events when a child is active, nor how touchStartPreventDefault interacts with this scenario. This creates a race condition that can produce inconsistent UX.

Questions

• Does the parent Swiper ignore touch events while a child Swiper is active when nested:true?
• How does the allowTouchMove setting on the parent influence this behavior?
• Are there observable differences between Swiper 8.x and 9.x regarding nested touch propagation?