Hi there,
I read the code and the implementation requires each federation member to submit a transaction to cast a vote. This means if it requires 3/5 members for the transaction to be valid, 3 separate transactions from the 5 members have to be sent. A more gas efficient way would be performing the transaction signatures off chain and validating all the signatures in a single transaction, something you guys have considered?
From this repo: GitHub - rsksmart/tokenbridge at 2bb458b4a3ee2f772b72c88c49ca544b5b6c85a4