Theme editor (custom-theme-visit-theme) shows only Lisp expressions for faces

I have a simple theme file (TL-theme.el in custom-theme-directory) which
contains this:


   (deftheme TL
     "Black background, blue tab bar and mode line.")

   (custom-theme-set-faces
    'TL
    '(cursor ((t (:background "#eee"))))
    '(mode-line ((t (:inherit variable-pitch :background "#44e"
                              :foreground "#eee"
                              :box (:line-width (2 . 2)
                                                :style released-button)))))
    '(mode-line-inactive ((t (:background "#447" :inherit mode-line))))
    '(tab-bar ((t (:foreground "#eee" :background "#447"
                               :inherit variable-pitch))))
    '(tab-bar-tab-inactive ((t (:background "#447" :inherit tab-bar-tab))))
    '(tab-bar-tab ((t (:box (:line-width (2 . 2) :style released-button)
                            :inherit tab-bar :background "#44e"
                            :foreground "#eee"))))
    '(fringe ((t (:background "#447"))))
    '(header-line ((t (:inherit mode-line :background "#447"
                                :foreground "#eee"
                                :box (:line-width (1 . 1)
                                                  :style flat-button)))))
    '(header-line-highlight ((t (:inherit mode-line-highlight))))
    '(mode-line-highlight ((t (:background "#77e"))))
    '(default ((t (:inherit nil :extend nil :stipple nil :background "#000"
                            :foreground "#eee" :inverse-video nil :box nil
                            :strike-through nil :overline nil :underline nil
                            :slant normal :weight normal :height 110
                            :width normal :family "DejaVu Sans Mono"))))
    '(menu ((t (:background "#44e" :foreground "#eee")))))

   (provide-theme 'TL)


The theme editor (M-x custom-theme-visit-theme RET TL RET) shows face
settings as Lisp expressions like this:

      [X] Hide [Tab Bar] face:              [sample]
       Tab bar face.
    Lisp expression: 
    ((t (:foreground "#eee" :background "#447" :inherit variable-pitch)))

I would like to have them in friendly customize format which I get if I
edit them with M-x customize-face RET tab-bar RET.

    Hide [Tab Bar] face: [sample]
       [ State ]: THEMED.
       Tab bar face.
       [X] Foreground: #eee           [ Choose ]  (sample)
       [X] Background: #447           [ Choose ]  (sample)
       [X] Inherit:
           [INS] [DEL] Face: [link] (sample) variable-pitch
           [INS]

Is it possible to configure the theme editor to use the proper customize
interface for face settings?

-- 
/// Teemu Likonen - .-.. https://www.iki.fi/tlikonen/
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