Rendering Two Dots Above a Character

[Omid Mo'menzadeh]

Hello all.
I am trying to create some sort of tablature for Kalimba, treating it like
a one-string instrument with fret-labels. I want to use letters like c, ċ,
ċ̇ (or c𐽉), etc. I figured there are Unicode characters to do exactly
that, "combining dot above" and "combining two dots above", etc. However,
LilyPond does not seem to be able to render "combining two dots above", and
two "combining dot above" characters (rendered correctly by my browser, as
well as Emacs) result in the two dots to be rendered almost on top of each
other in LilyPond. I have attached a rather minimal example.

I would appreciate any other solutions to this problem, or a way to fix the
rendering issue.

Thanks everyone.

%%% minimal example start
\version "2.22.1"

notes = \relative c' {
  \time 3/4
  c c' c' |
}

\score {
  <<
    \new StaffGroup = "tab with traditional" <<
      \new Staff = "standard" \with {
        midiInstrument = "kalimba"
        instrumentName = "Kalimba"
      } <<
        \clef "treble"
        \context Voice = "music" \notes
      >>
      \new TabStaff = "tab" \with {
        stringTunings = \stringTuning <c'>
        tablatureFormat = #fret-letter-tablature-format
        fretLabels = \markuplist {"c" "_" "d" "_" "e" "f" "_" "g" "_" "a" "_" "b" "ċ" "_" "ḋ" "_" "ė" "ḟ" "_" "ġ" "_" "ȧ" "_" "ḃ" "ċ̇" "_" "ḋ̇" "_" "ė̇"}
      } <<
        \tabFullNotation
        \context TabVoice = "tab" \notes
      >>
    >>
  >>
}
%%% minimal example end