Actually have tried this. Indeed it easily drops at room temperature like loose small flakes and powdery light brown stuff, but in the freezer it slowly drops darker and denser brown crystals. Room temp is certainly faster, but I wash the precipitant with clean acetone and if it is too powdery it likely loses some in clean acetone.

Haven't tested the darker material yet. Hopefully all of this replicates the two samples you ran in the tlc plates and both are equally active and safe.

Another question... Light or dark brown it doesn't seem soluble in ethyl acetate. Which one would be best for cleanup, acetone or EA?