diff --git a/python/biopro/devlib/domain.py b/python/biopro/devlib/domain.py
index e96a060..bc3f654 100644
--- a/python/biopro/devlib/domain.py
+++ b/python/biopro/devlib/domain.py
@@ -310,6 +310,8 @@ class ParameterValueDomain(ParameterDomain, metaclass=abc.ABCMeta):
                 return f
 
     def valid_para(self, value: Any) -> bool:
+        if isinstance(value, list):
+            return True
         f, t = self.range
         return f <= float(value) < t
 
@@ -612,8 +614,8 @@ class ParameterCollectionDomain(ParameterDomain, metaclass=abc.ABCMeta):
     def __init__(self, domain: ParameterDomain):
         super().__init__()
 
-        if isinstance(domain, ParameterCollectionDomain):
-            raise RuntimeError('cannot compose with parameter collection domain')
+        # if isinstance(domain, ParameterCollectionDomain):
+        #     raise RuntimeError('cannot compose with parameter collection domain')
 
         self._domain = domain
 
diff --git a/python/biopro/devlib/encoder.py b/python/biopro/devlib/encoder.py
index 045ab6d..567d992 100644
--- a/python/biopro/devlib/encoder.py
+++ b/python/biopro/devlib/encoder.py
@@ -119,7 +119,7 @@ class DeviceConfigurationEncoder:
                 e.write(b'L\0')
 
             else:
-                parameter_type = cls._value_type(value[0])
+                parameter_type = cls._value_type(min(value))
                 e.write(b'L')
                 e.write(parameter_type.encode())
                 e.u8(sz)
@@ -153,7 +153,8 @@ class DeviceConfigurationEncoder:
         if isinstance(value, bool):
             e.u8(1 if value else 0)
 
-        elif isinstance(value, str):
+        elif isinstance(value, str) or isinstance(value, list):
+            value = str(value)
             e.encode_string(value)
 
         elif isinstance(value, int):
@@ -170,7 +171,7 @@ class DeviceConfigurationEncoder:
         if isinstance(value, bool):
             return '?'
 
-        elif isinstance(value, str):
+        elif isinstance(value, str) or isinstance(value, list):
             return 'p'
 
         elif isinstance(value, int):