diff --git a/mantle/cmd/kola/options.go b/mantle/cmd/kola/options.go
index e54050627506a7b4287e27ba7299435dcbd06e65..9ba44f403bad5c8e9dd3dc4c3d979c98897356c9 100644
--- a/mantle/cmd/kola/options.go
+++ b/mantle/cmd/kola/options.go
@@ -69,6 +69,8 @@ func init() {
 	sv(&kola.Options.CosaWorkdir, "workdir", "", "coreos-assembler working directory")
 	sv(&kola.Options.CosaBuildId, "build", "", "coreos-assembler build ID")
 	sv(&kola.Options.CosaBuildArch, "arch", coreosarch.CurrentRpmArch(), "The target architecture of the build")
+	sv(&kola.Options.AppendButane, "append-butane", "", "Path to Butane config which is merged with test code")
+	sv(&kola.Options.AppendIgnition, "append-ignition", "", "Path to Ignition config which is merged with test code")
 	// we make this a percentage to avoid having to deal with floats
 	root.PersistentFlags().UintVar(&kola.Options.ExtendTimeoutPercent, "extend-timeout-percentage", 0, "Extend all test timeouts by N percent")
 	// rhcos-specific options
diff --git a/mantle/platform/cluster.go b/mantle/platform/cluster.go
index 7a9b283e807ff739fa175fb9f9de792a79c470b5..51e804a76211cfb321423c5e3dfe65802db951f8 100644
--- a/mantle/platform/cluster.go
+++ b/mantle/platform/cluster.go
@@ -196,10 +196,63 @@ func (bc *BaseCluster) RenderUserData(userdata *platformConf.UserData, ignitionV
 		userdata = userdata.Subst(k, v)
 	}
 
-	conf, err := userdata.Render(bc.rconf.WarningsAction)
+	confSources := []*platformConf.Conf{}
+
+	// Gather the base config
+	baseConf, err := userdata.Render(bc.rconf.WarningsAction)
 	if err != nil {
 		return nil, err
 	}
+	// We may have multiple config sources; create an array now
+	// with that sole element.
+	confSources = append(confSources, baseConf)
+
+	// If butane is specified, parse and add that.
+	if bc.bf.baseopts.AppendButane != "" {
+		buf, err := os.ReadFile(bc.bf.baseopts.AppendButane)
+		if err != nil {
+			return nil, err
+		}
+		subData := platformConf.Butane(string(buf))
+		subConf, err := subData.Render(platformConf.ReportWarnings)
+		if err != nil {
+			return nil, err
+		}
+		confSources = append(confSources, subConf)
+	}
+
+	// If Ignition is specified, parse and add that.
+	if bc.bf.baseopts.AppendIgnition != "" {
+		buf, err := os.ReadFile(bc.bf.baseopts.AppendIgnition)
+		if err != nil {
+			return nil, err
+		}
+		subData := platformConf.Ignition(string(buf))
+		subConf, err := subData.Render(platformConf.ReportWarnings)
+		if err != nil {
+			return nil, err
+		}
+		confSources = append(confSources, subConf)
+	}
+
+	// Look at the array of configs we have so far; if there is exactly one,
+	// then we don't need to do any merging.
+	var conf *platformConf.Conf
+	if len(confSources) == 1 {
+		conf = confSources[0]
+	} else {
+		// There are multiple configs; we now default to merging
+		// them all into a new Ignition config.
+		userdata, err := platformConf.MergeAllConfigs(confSources)
+		if err != nil {
+			return nil, err
+		}
+
+		conf, err = userdata.Render(platformConf.ReportWarnings)
+		if err != nil {
+			return nil, err
+		}
+	}
 
 	for _, dropin := range bc.bf.baseopts.SystemdDropins {
 		conf.AddSystemdUnitDropin(dropin.Unit, dropin.Name, dropin.Contents)
diff --git a/mantle/platform/platform.go b/mantle/platform/platform.go
index 7e038d55795d3738c014c4ca62a696c0d519dfc1..56e45f6da9a51ab9e00204eb3ac1da5bf12cf73a 100644
--- a/mantle/platform/platform.go
+++ b/mantle/platform/platform.go
@@ -184,6 +184,9 @@ type Options struct {
 
 	UseWarnExitCode77 bool
 
+	AppendButane   string
+	AppendIgnition string
+
 	// OSContainer is an image pull spec that can be given to the pivot service
 	// in RHCOS machines to perform machine content upgrades.
 	// When specified additional files & units will be automatically generated