Collision with dotted half rests

[jeandeaual]

I noticed a collision happens when using dotted half rests (r2.), with doesn't happen with dotted half notes:

I'd like to fix this issue but I'm not sure where the dot is generated in the code. Do you have any pointers?

Here is the code used for testing:

\version "2.20.0"

\include "shamisen.ly"

#(set-global-staff-size 32)

\header {
  tagline = ##f
}

\paper{
  page-breaking = #ly:one-line-auto-height-breaking
  #(define fonts
    (set-global-fonts
     #:roman "IPAexGothic"
     #:factor (/ staff-height pt 20)
    ))
}

\score {
  \new TabStaff \with { stringTunings = #niagariTuning } {
    \shamisenNotation
    \time 4/4

    g2. g4 |
    r2. r4 |

    \bar "|."
  }
}

[jeandeaual]

I'd also like to move the elongation line down or up a line when on the 1st or 3rd string. For now they have the same position regardless of which string is used: