Update knowledge_base.rst

Author: beckermr

src/maintainer/knowledge_base.rst

@@ -1258,8 +1258,9 @@ Apple Silicon builds
 The new Apple M1 processor is the first Apple Silicon supported by conda-forge
 `osx-arm64 <https://github.com/conda-forge/conda-forge.github.io/issues/1126>`_ builds.
 For new builds to be available, via cross-compilation, a migration is required for
-the package and its dependencies. To request a migration for a particular package
-and all its dependencies:
+the package and its dependencies. These builds are experimental as many of them are untested.
+
+To request a migration for a particular package and all its dependencies:
 
 1. Check the feedstock in question to see if there is already an issue or pull request.
    Opening an issue here is fine, as it might take a couple iterations of the below,