diff --git a/test/categorical_algebra/CatElements.jl b/test/categorical_algebra/CatElements.jl
index 21b9ef184..2363f4efb 100644
--- a/test/categorical_algebra/CatElements.jl
+++ b/test/categorical_algebra/CatElements.jl
@@ -1,6 +1,63 @@
 module TestCatElements
 using Test
 using Catlab.GATs, Catlab.Theories, Catlab.Graphs, Catlab.CategoricalAlgebra
+import Catlab.CategoricalAlgebra.CSets: ACSetTransformation
+import ACSets
+import ACSets: ACSet, acset_schema, add_parts!, codom_parts, dom_parts,
+  has_part, has_subpart, incident, IntParts, nparts, parts, set_subpart!,
+  subpart
+
+struct WrappedGraph <: ACSet{IntParts}
+  data::Graph
+end
+WrappedGraph() = WrappedGraph(Graph())
+
+acset_schema(::WrappedGraph) = acset_schema(Graph())
+nparts(g::WrappedGraph, p::Symbol) = nparts(g.data, p)
+parts(g::WrappedGraph, p::Symbol) = parts(g.data, p)
+add_parts!(g::WrappedGraph, p::Symbol, n::Int) = add_parts!(g.data, p, n)
+set_subpart!(g::WrappedGraph, part::Int, f::Symbol, val) =
+  set_subpart!(g.data, part, f, val)
+subpart(g::WrappedGraph, f::Symbol) = subpart(g.data, f)
+subpart(g::WrappedGraph, part, f::Symbol) = subpart(g.data, part, f)
+subpart(g::WrappedGraph, names::Tuple{Vararg{Symbol}}) = subpart(g.data, names)
+subpart(g::WrappedGraph, part, names::Tuple{Vararg{Symbol}}) =
+  subpart(g.data, part, names)
+dom_parts(g::WrappedGraph, f::Symbol) = dom_parts(g.data, f)
+codom_parts(g::WrappedGraph, f::Symbol) = codom_parts(g.data, f)
+has_part(g::WrappedGraph, p::Symbol) = has_part(g.data, p)
+has_subpart(g::WrappedGraph, f::Symbol) = has_subpart(g.data, f)
+incident(g::WrappedGraph, part, f::Symbol) = incident(g.data, part, f)
+incident(g::WrappedGraph, part, names::Tuple{Vararg{Symbol}}) =
+  incident(g.data, part, names)
+ACSetTransformation(components, X::WrappedGraph, Y::WrappedGraph) =
+  ACSetTransformation(components, X.data, Y.data)
+
+@testset "Custom ACSet category-of-elements APIs" begin
+  arr = path_graph(Graph, 2)
+  wrapped_arr = WrappedGraph(arr)
+  @test elements(wrapped_arr) == elements(arr)
+
+  wrapped_two_edge = WrappedGraph(path_graph(Graph, 3))
+  el_wrapped_two_edge = elements(wrapped_two_edge)
+  @test nparts(el_wrapped_two_edge, :El) == 5
+  @test nparts(el_wrapped_two_edge, :Arr) == 4
+
+  round_trip_wrapped = inverse_elements(el_wrapped_two_edge, WrappedGraph())
+  @test nparts(round_trip_wrapped, :V) == 3
+  @test nparts(round_trip_wrapped, :E) == 2
+  @test subpart(round_trip_wrapped, :src) == [1, 2]
+  @test subpart(round_trip_wrapped, :tgt) == [2, 3]
+
+  graph_two_edge = path_graph(Graph, 3)
+  graph_hom = homomorphism(arr, graph_two_edge; initial=(V=[1, 2], E=[1]))
+  el_hom = elements(graph_hom)
+  inv_wrapped_hom = inverse_elements(el_hom, WrappedGraph())
+  @test nparts(dom(inv_wrapped_hom), :E) == 1
+  @test nparts(codom(inv_wrapped_hom), :E) == 2
+  @test collect(force(inv_wrapped_hom)[:V]) == [1, 2]
+  @test collect(force(inv_wrapped_hom)[:E]) == [1]
+end
 
 arr = @acset Graph begin
   V = 2
diff --git a/mimo_test_command.sh b/mimo_test_command.sh
new file mode 100755
--- /dev/null
+++ b/mimo_test_command.sh
@@ -0,0 +1,60 @@
+#!/bin/bash
+set -uo pipefail
+cd /testbed
+
+
+set -e
+pkg_instantiate() {
+  if ! julia --project=. -e 'using Pkg; Pkg.instantiate()' > /tmp/fixture_pkg_instantiate.log 2>&1; then
+    cat /tmp/fixture_pkg_instantiate.log
+    return 1
+  fi
+}
+
+pkg_instantiate
+ACSETS_DIR=$(julia --project=. -e 'using ACSets; println(dirname(dirname(pathof(ACSets))))')
+sed -i 's/abstract type SimpleACSet{PT} <: ACSet{PT} end/abstract type SimpleACSet{PT<:PartsType} <: ACSet{PT} end/' "$ACSETS_DIR/src/DenseACSets.jl"
+sed -i 's/struct DynamicACSet{PT} <: SimpleACSet{PT}/struct DynamicACSet{PT<:PartsType} <: SimpleACSet{PT}/' "$ACSETS_DIR/src/DenseACSets.jl"
+rm -rf /root/.julia/compiled/v1.10/ACSets /root/.julia/compiled/v1.10/Catlab
+
+
+instantiate() {
+  pkg_instantiate
+}
+
+case "${1:-}" in
+  base)
+    instantiate
+    awk '
+      /^@testset "Custom ACSet category-of-elements APIs" begin$/ { skip=1; next }
+      skip && /^end$/ { skip=0; next }
+      !skip { print }
+    ' test/categorical_algebra/CatElements.jl > /tmp/cat_elements_base.jl
+    julia --project=. /tmp/cat_elements_base.jl
+    ;;
+  new)
+    instantiate
+    printf '%s\n' 'module FixtureDynamicCatElements' > /tmp/cat_elements_dynamic.jl
+    printf '%s\n' 'using Test' >> /tmp/cat_elements_dynamic.jl
+    printf '%s\n' 'using Catlab.GATs, Catlab.Theories, Catlab.Graphs, Catlab.CategoricalAlgebra' >> /tmp/cat_elements_dynamic.jl
+    set +e
+    awk '
+      /^import Catlab.CategoricalAlgebra.CSets: ACSetTransformation$/ { capture=1 }
+      capture && /^arr = @acset Graph begin$/ { found=1; exit }
+      capture { print }
+      END { if (!found) exit 3 }
+    ' test/categorical_algebra/CatElements.jl >> /tmp/cat_elements_dynamic.jl
+    awk_status=$?
+    set -e
+    printf '%s\n' 'end # module' >> /tmp/cat_elements_dynamic.jl
+    if [ "$awk_status" -ne 0 ]; then
+      echo "Custom ACSet testset not found in CatElements test file"
+      exit "$awk_status"
+    fi
+    julia --project=. /tmp/cat_elements_dynamic.jl
+    ;;
+  *)
+    echo "usage: $0 base|new"
+    exit 2
+    ;;
+esac