Do all implementation of Deterministic RFC6979-compliant ECDSA signatures generate the same signed transaction given the same data? So if I were to create the same transaction using bitcoinjs and bitcoinj, the end result of the signed transaction would be the same with both libraries, is that correct?
So if I were to create the same transaction using bitcoinjs and bitcoinj, the end result of the signed transaction would be the same with both libraries, is that correct?


They certainly should. That's why they're called deterministic. Any particular library could have a bug in it, however. I would check against examples given in the spec to make sure a library is compliant with the spec, or run the unit tests if the library you're using has them.