They are small LEDs that only draw a few mA each though.
I also have an RGBW blade, which prevents me from doing SubBlade on the PCB and thus the need for separate data lines. I think that in the future I will simply deprecate that blade.
It’s been on my TODO list for a long long time to make it possible to mix RGB and RGBW pixels in subblade. It’s definitely possible to do, but it requires rewriting some of the code to support it.