diff --git a/NEWS.md b/NEWS.md
index f4ddc71..cfaa964 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,16 @@
 # Release notes
 
+## Version 0.5.4 (2024-09-09)
+
+### Bugfix
+
+* Fix incorrect ylabel when using scale_tot_opex=true.
+
+### Enhancement
+
+* Improve performance with a workaround for slicing a JuMP.Containers.SparseAxisArray.
+* Enable collect for ::EnergySystemDesign by providing the function length(::EnergySystemDesign).
+
 ## Version 0.5.3 (2024-09-02)
 
 ### Bugfix
diff --git a/Project.toml b/Project.toml
index 7328126..178b895 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "EnergyModelsGUI"
 uuid = "737a7361-d3b7-40e9-b1ac-59bee4c5ea2d"
 authors = ["Jon Vegard Venås <JonVegard.Venas@sintef.no>", "Magnus Askeland <Magnus.Askeland@sintef.no>", "Shweta Tiwari <Shweta.Tiwari@sintef.no>"]
-version = "0.5.3"
+version = "0.5.4"
 
 [deps]
 CairoMakie = "13f3f980-e62b-5c42-98c6-ff1f3baf88f0"
diff --git a/docs/src/figures/EMI_geography.png b/docs/src/figures/EMI_geography.png
index 15d088c..ac4863c 100644
Binary files a/docs/src/figures/EMI_geography.png and b/docs/src/figures/EMI_geography.png differ
diff --git a/docs/src/figures/example.png b/docs/src/figures/example.png
deleted file mode 100644
index 3b5ef53..0000000
Binary files a/docs/src/figures/example.png and /dev/null differ
diff --git a/src/datastructures.jl b/src/datastructures.jl
index c68d637..6bb2f7c 100644
--- a/src/datastructures.jl
+++ b/src/datastructures.jl
@@ -226,6 +226,7 @@ function Base.iterate(itr::EnergySystemIterator, state=nothing)
     return itr.stack[idx], idx
 end
 Base.length(itr::EnergySystemIterator) = length(itr.stack)
+Base.length(design::EnergySystemDesign) = length(EnergySystemIterator(design))
 
 function Base.iterate(design::EnergySystemDesign, state=(nothing, nothing))
     itr = isnothing(state[2]) ? EnergySystemIterator(design) : state[2]
diff --git a/src/utils_GUI/GUI_utils.jl b/src/utils_GUI/GUI_utils.jl
index 291c2cd..ff53f77 100644
--- a/src/utils_GUI/GUI_utils.jl
+++ b/src/utils_GUI/GUI_utils.jl
@@ -240,20 +240,17 @@ function initialize_available_data!(gui)
 
             for combination ∈ get_combinations(var, i_T)
                 selection = collect(combination)
-                if isa(var, SparseVariables.IndexedVarArray)
-                    field_data = JuMP.Containers.SparseAxisArray(
-                        Dict(
-                            (t,) =>
-                                var[vcat(selection[1:(i_T - 1)], t, selection[i_T:end])...]
-                            for t ∈ periods
-                        ),
+                if isa(var, SparseVars) # Slicing for SparseVars performs worse than the following
+                    field_data = JuMP.Containers.DenseAxisArray(
+                        [
+                            var[vcat(selection[1:(i_T - 1)], t, selection[i_T:end])...] for
+                            t ∈ periods
+                        ],
+                        periods,
                     )
-                else
+                else # For DenseAxisArrays, slicing performs best
                     field_data = var[vcat(selection[1:(i_T - 1)], :, selection[i_T:end])...]
                 end
-                if isempty(field_data)
-                    continue
-                end
                 element::Plotable = getfirst(
                     x -> isa(x, Union{EMB.Node,Link,Area,TransmissionMode}), selection
                 )
@@ -338,8 +335,8 @@ function initialize_available_data!(gui)
 
         # add total operational cost to available data
         description = "Total operational cost"
-        if scale_tot_capex
-            description *= " (scaled to year)"
+        if scale_tot_opex
+            description *= " (scaled to strategic period)"
         end
         container = Dict(
             :name => "tot_opex",
@@ -486,7 +483,7 @@ end
 Get an iterator of combinations of unique indices excluding the time index located at index `i_T`.
 """
 function get_combinations(var::SparseVars, i_T::Int)
-    return unique([(key[1:(i_T - 1)]..., key[(i_T + 1):end]...) for key ∈ keys(var.data)])
+    return unique((key[1:(i_T - 1)]..., key[(i_T + 1):end]...) for key ∈ keys(var.data))
 end
 function get_combinations(var::JuMP.Containers.DenseAxisArray, i_T::Int)
     return Iterators.product(axes(var)[vcat(1:(i_T - 1), (i_T + 1):end)]...)