There is a (very) thin space that shouldnʼt be there between the 1f44d and the '|' on the line that has the FE0F (and since it follows the value of glyphless-char-display-control, I donʼt think it comes from the shaping engine). but (set-char-table-range composition-function-table #x1F44D '(["\U0001f44d\ufe0f" 0 font-shape-gstring])) gives me this, where the two '|' align perfectly.