As font mcmeta is not implemented yet, the only satisfying way to make custom font for symbols, which is not implemented in ascii-set, was customisation of font.txt, which was removed in S13w42a. Ofc, there's the other way - editing the glyph_sizes.bin, but with every expanded character there appears a padding in the end of each string (see screenshots).
So... yes, i know that font meta is likely not ready yet, but could you give us any other solution?