Thanks
@JaxTerminal. This pic is old so is kinda fuzzy, but if you enlarge it to max res and look closely, it looks to me (based upon the end logos) that some of the 'blank' blue containers may be the HJCU:

Not sure either if those are standard height or HCs.
Are you also perhaps thinking of some SENUs? I haven't been able to find any other than for the long-extinct DIs.
(That pic also makes me pine for the TwinStacks and LoPacs

)
Ed