Storage layout conflicts are a concern when using patterns with delegatecalls (https://mixbytes.io/blog/collisions-solidity-storage-layouts). Our MutableForwarder is simple enough to keep track of this and its simplicity is an advantage, but it could also be considered to use some well established Proxy implementation that would hide the storage concerns from our code.
Summary
resolves #188
Review notes
Storage layout conflicts are a concern when using patterns with delegatecalls (https://mixbytes.io/blog/collisions-solidity-storage-layouts). Our MutableForwarder is simple enough to keep track of this and its simplicity is an advantage, but it could also be considered to use some well established Proxy implementation that would hide the storage concerns from our code.