The only thing one could do better would be to make an eight LED module that buffers the LED inputs, and allows stacking end to end with consistent nibble spacing and white silkscreen space to write on. e.g. 'D7-D4 D3-D0'
I haven't used a breadboad in years, but you're preaching to the choir. I made a couple of 8 channel logic probes for this, probably over a decade ago. Fully buffered Mohms input, hi/lo/hi-Z dual color LED indicators. Each channel has DIP switch selectable pullup or pulldown or float. Each channel can also be used as a manual tactile switch input, DIP selectable to pull to power or ground (through a 30 ohm resistor to avoid accidental direct shorts). The latter case, it's nice that the LED indicators are there, so you know when the switches have gone bad! Integrated battery to provide 5V power to both the probe and the circuit. Or the internal PSU be used to only power the logic probe array with 5V, to make it work with arbitrary external logic. Or the external circuit can power both the logic bus and the probe, all through DIP switches and a diagram stuck on the bottom. (One of them also has a 3.3V regulator for driving the circuit with either 5V or 3.3V). I/O connections via 0.1 inch spacing headers, and a second header for optionally plugging it into an 8 channel logic analyzer. This was made before I even did PCB in CAD, but there's no good way to really design this board unless you use multiple layers. Wires are crisscrossing everywhere, and the LED array is glued over the top of the 4x quad opamp IC's to save space. It's compact for what it is.
And yeah, I sometimes have squeezed a strip of label tape in there to give a tiny place to label the channels. I also made a screw on coverplate that you can just draw/write on.
But plugable single LED modules (0.1" wide) are fantastic for breadboard work; no wires! Both are useful.
If you want to use a multi LED bar/array like the way you're describing, there's no need for it to have 0.1" spacing of the LEDs and to plug into the board, at all. Just put it on a veroboard along with the resistors and add a pin header to it. Hot snot it to the edge of the breadboard and plug your jumpers in. One jumper to connect the common rail and one for each individual LED. My 8 channel logic probes are too big to plug into the board. They just lay next to the breadboard. Or if need be, and you're going to move this around, I glue the breadboard to a backerboard, and glue the probe to the backerboard to make them all one piece. But it's easy enough to just wire up a circuit-specific harness and be able to plug the whole unit in/out, which is what I do when using it with PCB circuits rather than breadboard.