@miles I’ve moved these posts into their own thread so that they don’t get lost in the just chatting milieu.
no, there is no way to upload data files into makecode but there is a much more efficient way to include them in your program. see this post where i gave a sample script for converting number arrays into hex buffers:
as for what you want to do, i’d say that if you wanted to edit the C++ then you might be better off adding straight up sample playback rather than doing some waveform trickery to better approximate the sound. then you could write a script to convert your sample to PCM data and have the C++ code play that back.
we do have sample playback implemented in some of our other targets (micro:bit) it just hasn’t made its way to arcade yet.