Font Custom's intended sweet spot lies somewhere between using a pre-bundled icon font and firing up a fully-fledged glyph editor. For the simplicity of using regular vectors, I think the lack of perfect pixel hinting could be a worthwhile tradeoff.
Unfortunately, I demand icon font being sharp at particular font size. Ideally, you could provide a set of eps/svg files with pixel grids and UPM (units per eM) generator setting for the desired font sizes (eg 16px, 20px, 24px). Is it possible?
Can you see yourself using the tool as it is?