First, a quick video…
I’ve hit a problem… my Eurorack plans require 22-23 power connections, and I only have 20 provided by my Make Noise case. Assuming that the power supply is sufficient, I can use a flying bus cable to add some more power connection points.
I bought the Synthrotek Deluxe 10 Connection Flying Bus Cable from Amazon because I figured 10 additional connections ought to be more than enough. The cable is actually long enough to add connections to across the case, but I wanted to cut it in half to show that it’s possible to still use the cable since it has the proper connector on both ends as you can see below.

Obviously you can use similar flying bus cables that just have one power connector end, but if you only need a few more connections someplace localized, this may be a solid solution for you as a way to get a few more connections into your case where you need them.
I do want to note, because I didn’t go into it in the video, but you’ll want to make sure you’re case isn’t drawing more power than the case can provide, as this can lead to damage either your gear or your power supply. Using a tool like modular grid will help you get a ballpark for power usage in your case so you can get a sense for how much you are using versus how much the power supply can provide.