@Lugia - yeah - I kind of know what you mean, but I'd call it moving basic utilities into the "expensive" row:
the cost of the 1u row is the same as that of a 3u row in terms of rails, inserts/nuts, screws
the difference in case material is generally negligible - unless possibly made from a very rare wood
hp for hp tiles are less functionally dense than 3u modules so will only cover 1/3rd the functionality or so
and all to save 3.5"...
better to get an extra row of 3u unless there is some overwhelming reason - & the only real one I can think of is overhead baggage size limits
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities