Line 337 - Transport costs also include transmission costs and distribution costs. These costs do not typically vary unlike the congestion charge which is an adder to the price, and losses are typically purchased by the buyer.

Agreed - and this is what the schema suggests. Because the current distinctions between Transmission costs and Distributions costs are arbitrary and historic, and each may change in the future, and some other combination may be used in, say, microgrids, this produce contains all options, but does nto require all options.