Why would you send an actual dict instead of a proplist? Every serialization protocol I am aware of does not send the actual internal dict/hash/map representation but instead flattens it down to what is effectively a list of key-value pairs that may or may not be tagged by the protocol as something to be reconstituted as a dict at the remote end. Looking at the spec it appears that this is what BERT does as well.
Because the result in Erlang will not be a dict, it will be a list of key/value pairs. That's not the same.
Doing that automatically means you have to do something else to label it as a key/value list meant to back to a dict.
These are not insurmountable problems, just issues that have to be dealt with. Any problem in Erlang can be solved with another layer of record indirection, but those don't come for free.
I must not have looked closely enough to find the source; I did try.
