The newest Electrum server utilizes a Patricia tree data structure to provide full UTXO history.

The server indexes UTXOs by address, in a Patricia tree structure described by Alan Reiner (see the ‘ultimate blockchain compression’ thread in the Bitcointalk forum)

Can Electrum server provide the same data as Insight?

Development is ongoing of electrum-server, but I think it’s works to have Counterparty in Electrum directly.