display plot is slow

[clouds56]

@time using Plots # tag-import
import Markdown
@time for (d, feat) in collect(zip(data, feats))[1:3] # tag-all: takes >300s
  @time display(Markdown.parse("## `$feat`")) # tag-md
  colnames = propertynames(d)
  @time plots = [Feat.plot_feat(d[!, colname]; name=colname) for colname in colnames] # tag-plot: takes average ~2s
  @time display(@time plot(plots..., layout=(length(plots), 1), size=(800, 300*length(plots)))) # tag-inner: inner average <1s, tag-outer: outer takes [30, 120, 150] seconds
end

I think this is not related to first plot time and actually there's something wrong inside display, the time seems increasing (the output plot is almost the same)

output like this

tag-import:  0.000372 seconds (137 allocations: 9.891 KiB)
tag-md    :   0.000228 seconds (134 allocations: 8.344 KiB)
tag-plot  :   2.727499 seconds (409.84 k allocations: 960.588 MiB, 8.04% gc time, 29.44% compilation time)
tag-inner :   0.231747 seconds (8.08 k allocations: 175.876 MiB, 41.44% gc time)
tag-outer :  30.318927 seconds (24.10 M allocations: 1.392 GiB, 1.99% gc time)
tag-md    :   0.000184 seconds (133 allocations: 8.438 KiB)
tag-plot  :   1.634230 seconds (69.91 k allocations: 940.056 MiB, 8.27% gc time)
tag-inner :   0.088039 seconds (8.07 k allocations: 175.872 MiB)
tag-outer : 126.838568 seconds (23.95 M allocations: 1.387 GiB, 0.52% gc time)
tag-md    :   0.000234 seconds (133 allocations: 8.500 KiB)
tag-plot  :   1.874118 seconds (69.91 k allocations: 940.056 MiB, 7.38% gc time)
tag-inner :   0.238603 seconds (8.07 k allocations: 175.868 MiB, 48.30% gc time)
tag-outer : 154.335929 seconds (23.94 M allocations: 1.387 GiB, 0.46% gc time)
tag-all   : 317.732765 seconds (72.54 M allocations: 6.940 GiB, 0.77% gc time, 0.25% compilation time)

[clouds56]

I find out that the actual render would be done in display.