I have found other threads/questions related to bitmaps and fonts but I think my usage case is atypical.
This is for a very casual group project designing a font together. A group of non-artists has created a set of font characters in color bitmap form (PNGs with alpha). These are not vectorized, not suitable for vectorization. The goal is simply to put all the existing bitmaps together into a font that can be installed and used and to get the basic metrics (baseline, x-height, that sort of stuff) lined up. Approximately.
We know it will look terrible when scaled to various point sizes. We know it won't print nicely. We're fine with that. It's very, very casual.
I am not a FontForge user, I've tried to pick it up and am running into a roadblock. In particular, I can import my bitmaps into the character designer/"outline glyph view" using File-->Import, but the bitmap always seems to be in the "background" layer and I don't know how to move it to the foreground (if that can be done). The bitmap in the background does not seem to be used when generating "bitmap strikes" and when I try generating the font (to TrueType) the glyphs I've populated simply don't appear, all I see is blank/white.
Is there some technique I can use in FontForge to make these bitmaps usable more or less directly, without tracing or other vectorization? If not FontForge, is there another free Windows app with suitable features to accomplish this?