bug#36454: 26.2.90; feature request - Insert char by hex tab completion or C-x 8 RET ffe <TAB>

[VanL]

Hello Emacs,

This is a feature request for 'Insert character (Unicode name or hex)'
to include 'hex tab completion'.  For example, to use one of the ffe
common prefix arrow symbols from unicode.

Type:
-input-  C-x 8 RET
-output- Insert character (Unicode name or hex):
-input-  ffe <TAB>

Expect Emacs's response to include hex tab completions for 'ffe <TAB>'

  ￩ ffe9
  ￪ ffea
  ￫ ffeb
  ￬ ffec

But, Emacs's response only has Unicode name completion, like GIRAFFE FACE.

-output- Making completion list...
-- quote
   Click on a completion to select it.
   In this buffer, type RET to select the completion near point.
   
   Possible completions are:
   DIFFERENCE BETWEEN (≏)       GIRAFFE FACE (🦒)
   MATHEMATICAL BOLD ITALIC PARTIAL DIFFERENTIAL (𝝏)
   MATHEMATICAL BOLD PARTIAL DIFFERENTIAL (𝛛)
   MATHEMATICAL ITALIC PARTIAL DIFFERENTIAL (𝜕)
   MATHEMATICAL SANS-SERIF BOLD ITALIC PARTIAL DIFFERENTIAL (𝟃)
   MATHEMATICAL SANS-SERIF BOLD PARTIAL DIFFERENTIAL (𝞉)
   PARTIAL DIFFERENTIAL (∂)     SIGNWRITING CHEEKS PUFFED (𝨪)
   STUFFED FLATBREAD (🥙)
-- quote ends --