Making Precise Filter Shapes with DC Signals

Hello folks, this is less a question and more a sharing of methods:

I'm working on making a precise filter/EQ with FFT, but needed a way to store the scaling values for each FFT bin's level, and thus, the level of each frequency. To that end, I recorded a DC signal at the same length in samples as the FFT size (4096), then created an amplitude envelope for it in my DAWs audio editor.

Exporting that as a wav then dropping it into a buffer, which I then index using the FFT bin number, and multiplying the respective FFT value by this figure allows scaling of each bin according to my "EQ curve".

I'm also hoping that using a data buffer will allow users to import their own curves once the patch is exported as a VST but I haven't verified this yet. This was the only way I could come up with so far to get precise EQ in RNBO and also give the user some semblance of control over it as a VST (given multisliders don't exist in RNBO currently, and wouldn't render to the UI anyway).

If this helps anyone with their patching, then great. Alternatively, if you can come up with a better method for this, then please share!