as per the lietrature, for modeling an inline structure, only 4 cross sections are required. The cross section that is immediately upstream and downstream of the inline structure shall form the geometry for the inline.
I dont think that an inline can be traversed over multiple cross sections. it is not possbile i think.
That would depend if they are using the inline structure feature in HEC-RAS or if they are modeling the inline structure as only cross-sections instead of the inline structure option.