Beams and staff line thickness

[Noeck]

Hi,

when playing with staff line thicknesses, I encountered the following
problem:

\relative {
  \override Staff.StaffSymbol.thickness = #4
  c''8 g a a
}

In general, I thought Lilypond scales a lot of thicknesses and distances
according to staff lines and staff spaces. But here the beams don’t
start and end aligned with the stems but more centered on the stems.
With normal staff symbol thickness this looks ok (although I can’t tell
at 300% zoom).

Should I just not play with this thickness in that uncoordinated way or
is that an issue?

Cheers,
Joram