Remove signcolumn in fern

[NgoHuy]

I use fern and saw that some extraline in left side, one signcolumn and ~, I disable it on file buffer but no luck with fern. I read document and set signcolumn hide to 1 but no luck.
It looks like this

[lambdalisue]

Because fern use signcolumn to

1. Show marks (Try mark action)
2. Show task indicator (for directory with tons of entries)

[NgoHuy]

does it mean that it cannot be disabled? thank you