The following section of the spec states how to handle automatically placed subgridded items within a masonry container, which are supposed to be consider in every possible track for sizing.

However, there is nothing clarifying the expectation for items with a definite grid position that are subgridded through an automatically placed submasonry. Is the expectation to have that definite position to be consider in "all tracks" within the parent grid axis, considering that it would be offset to the "possible" definite positions it could take?

If this is the expectation, then computing the "possible" tracks an item could be placed becomes very complex when multiple levels of subgridding occur, and it is relevant to have those resolved in order to create the virtual masonry items for the optimized algorithm.