The hole in place over capslock is for per key color customization because you have to hold caps lock and either tap, or hold+cycle f5/f6/f7 to change RGB colors, and it's difficult to see what the current color would be if your finger was covering the caps lock LED. The shine 4 and shine 5 are set up the exact same way as the Disco is. The cutout of the small circle LED hole for the second LED is there to make it easier for you to see what color you're selecting. I do understand the point about having that small circle LED serve a dual function of also being a caps lock LED indicator independently from the main caps lock LED, though. That would indeed be a better design choice, but keep in mind the Scroll lock and Numlock LED's also function as key indicators also.
The Ducky YOTG Went the other way with that, though.
The Ducky Year of the Goat has dedicated caps /scroll/numlock indicators above the number keypad, as SMD RGB LED's with chassis holes for them, with caps lock accepting a normal backlight pattern with all of the other keys, while also being a macro and set profile indicator, and per key color customization shown through the main caps and circle LED just like the Shine 4/5/Disco, but some have said the indicators which are between the calculator/volume keys and number keypad can be blocked and hard to see at an angle. But I guess you would probably prefer that method to the existing one? The Ducky One also has status indicator LED's, and the circle LED on the caps lock isn't used and has no LED at all in the hole (there's a hardware mod where you can solder in a LED yourself and route trace and signal from the dedicated caps LED area to it).
Caps also flashes when changing profile presets (FN+1 through FN+6), if they exist on the Disco as they do on the Shine 5, and for programming macros in profile 2-6 (No idea if macro mode exists on the Disco).