It seems strange to me that given all of the concerns about living space and color palette aboard ISS, the data/power/cooling ports for different mid-deck locker equivalent (MLE) express rack payloads are on the fronts of the lockers.
Why not have some kind of snap-in docking connector which includes all the necessary power, data, air, water, gas, and vacuum connections? This could go on the back of the locker instead of the front, and would therefore be out of the way of the astronauts.
Yes, it would mean the lockers would lose a tiny bit of interior space, since the locker design would now have to accommodate a pre-ordained set of connectors in a certain arrangement. But MLEs are already almost totally arbitrary anyway.
And yes — I realize that not all payloads use all the connectors — but that doesn't necessarily matter. One could simply have dead ends in the MLE for these, or even not connect those particular pipes to the dock.
Is it mostly historical, or is there a good reason locker connections are done the way they are?