With the help of Source Han Serif (思源宋体), one can pseudo-encode some unencoded glyphs, such as the following Chinese character:
One can do this through the use of their IDSes (Ideographic Description Sequences) and the 'ccmp' (Glyph Composition/Decomposition) GSUB feature.
The IDSes are
⿺ 辶⿳穴⿰月⿰⿲⿱幺長⿱言馬⿱幺長刂心 (traditional) and
⿺ 辶⿳穴⿰月⿰⿲⿱幺长⿱言马⿱幺长刂心 (simplified).
How can we do that in LaTeX?
(Note: the IDSes may not display normally on your computer!)