Is your feature request related to a problem? Please describe.
reset_hunk with range (maybe total buffer content) and reset_buffer will replace range lines with lines in hunks.

Describe the solution you'd like
Find all hunks and set lines one by one in the range. Maybe can set a limited value if the hunks are Intensive in the range.

Additional context
TBH, semantic tokens of coc.nvim and nvim-ufo use a lot of extmarks, that's the reason I want to replace Gread in fugitive with reset_buffer in gitsigns.