Improve warning raising condition and warning message in convnext (#…

…151)

ascent/models/components/encoders/convnext.py

@@ -86,6 +86,7 @@ def __init__(
             ValueError: When `len(expansion_rate)` is not equal to `num_stages`.
             ValueError: When `len(n_conv_per_stage)` is not equal to `num_stages`.
             ValueError: When `len(num_features_per_stage)` is not equal to `num_stages`.
+            Warning: When `return_skip` is set to True and the stem performs a pooling operation.
         """
         super().__init__()
 
@@ -207,11 +208,12 @@ def __init__(
         self.return_skip = return_skip
         self.strides = [[i] * dim if isinstance(i, int) else list(i) for i in strides]
 
-        if return_skip and 2 in self.strides[0]:
+        if return_skip and not all(s == 1 for s in self.strides[0]):
             warnings.warn(
                 "The stem performs a pooling operation and `return_skip` is set to True. The "
                 "resolution of the skip connections might be wrong and will cause an error if "
-                "paired with `UNetDecoder`."
+                "paired with `UNetDecoder`. The highest resolution output of the `UNetDecoder` "
+                "will be (input resolution / stride of the stem) rather than the input resolution."
             )
 
         # initialize weights