SUMMARY
As a user I don't want the unique modifier to have "_" as a hardcode first first character (as e.g. in "_01") but would rather appreciate the possibility to configure it, e.g.
{unique:2,"your character here"}

I'm using the following renaming scheme when importing pictures:
Date_Time(including unique modifier)_"author's initials"_"camera".ext
or more precicely:
[date:yyyy-MM-dd_hh-mm-ss]_BK_RX10.[ext]

OBSERVED RESULT
when renaming several pictures with some of the taken in the same second and therefore requiring the unique modifier they get renamed and imported in the following order:
  2022-08-06_11-45-42_01_BK_RX10
  2022-08-06_11-45-42_02_BK_RX10
  2022-08-06_11-45-42_BK_RX10
  2022-08-06_11-45-44_01_BK_RX10
  2022-08-06_11-45-44_BK_RX10
The third and last pictures are out of order as they would actually have to be the first and fourth one.

EXPECTED RESULT
With the possibility to configure the first character of the unique modifier to e.g. "-" I could rename and import my pictures in the correct order:
  2022-08-06_11-45-42_BK_RX10
  2022-08-06_11-45-42-01_BK_RX10
  2022-08-06_11-45-42-02_BK_RX10
  2022-08-06_11-45-44_BK_RX10
  2022-08-06_11-45-44-01_BK_RX10

ADDITIONAL INFORMATION
With this being my first  bug report / feature request please don't be to hard on me...