Feedback - Accept Payments Through Top Level Customer

As mentioned in other UG threads, we are discussing how the 'Accept Payments Through Top Level Customer' feature can be enhanced to better meet our customers' needs in the future.
If you use or are interested in this feature, I would appreciate your feedback on the following questions:

1a. How many levels deep of parent/child customers do you use?

1b. Do you create invoices for mid-level parents & the top level parent, or always to the lowest level sub-customers?  It would be helpful to better understand real world business cases for how hierarchies are used.

1c. If your trees go deeper than just 1 level of parent/child, is it critical to be able to accept payments through any customer in the hierarchy, top level only (like today), or lowest level and top level (but not necessarily parents in the middle)?