My conclusions are about the same as yours - it looks like "roll your own" time.

The IPC::Sharable module basically serializes the shared variable, transports it, then re-creates it (with fancy locking and 2-way Ties). I don't see any way to avoid the serialization/re-assembly.

You could potentially re-design your app such that instead of exposing the data, you expose methods to manipulate the data. Then your problem comes down to (relatively) simple RPC.