[BUG] link=:y doesn't work across nested subplots with layout

[cstjean]

Details

plot(plot([1,2]), plot([3,4]), 
	 plot([-1,-2]), plot([3,-4]), layout=(2,2),
     link=:y)

generates linked plots, but

plot(plot(plot([1,2]), plot([3,4]), layout=(2,1)), 
	 plot(plot([-1,-2]), plot([3,4]), layout=(2,1)),
     link=:y)

doesn't (top plots' yrange isn't linked):

Backends

This bug occurs on ( insert x below )

Backend	yes	no	untested
gr (default)	X
pythonplot			X
plotlyjs			X
pgfplotsx			X
unicodeplots			X
inspectdr			X
gaston			X

Versions

Plots.jl version: v1.40.4
Backend version (]st -m <backend(s)>):
Output of versioninfo():

[isentropic]

I kinda understand why this happens, but I also thing this could be a feature rather than a bug. It is because each plot(...) returns different objects and ylink doesn't know about the existance of the outer plot in case you do it the second way

[cstjean]

For context, I basically have (in pseudocode)

model_plots(m::Model) = plot(plot(m.efficiency), plot(m.yield); layout=(2,1))

compare_models(m1::Model, m2::Model) = plot(model_plots(m1), model_plots(m2), link=:y)

To me that feels very natural. Is there a better way of structuring that code?