`twiny` in Plots somehow break the subplot margin

Specific Domains Visualization
1

Hi,

For a subplot to have tight margins, i did this and plot looks fine.

p=plot(layout=(1,3),leg=false)
for i in 1:3
    leftmargin = i==1 ? 6Plots.mm : -4Plots.mm
    heatmap!(p[i],rand(10,10),yticks=[];leftmargin)
end
p

image

but when i add a twiny for each subplots, it breaks the margins.

p=plot(layout=(1,3),leg=false)
for i in 1:3
    leftmargin = i==1 ? 6Plots.mm : -4Plots.mm
    heatmap!(p[i],rand(10,10),yticks=[];leftmargin)
    plot!(twiny(p[i]),rand(10),1:10;lw=2,leg=false,leftmargin)
end
p

image

Interestingly, set margin to same value for all subplots, would not break margins:

p=plot(layout=(1,3),leg=false)
for i in 1:3
    leftmargin =  -4Plots.mm
    heatmap!(p[i],rand(10,10),yticks=[];leftmargin)
    plot!(twiny(p[i]),rand(10),1:10;lw=2,leg=false,leftmargin)
end
p

image

is there a way to set different margins for each subplots with twiny?

Thanks,
Alex