There is a difference between the provisional government leader in ‘61 and his inaugeration as the official president of the Confederacy in ‘62.
He did not have the authority to make treaties as the provisional head of state until after the elections in 1961, where he was acclaimed.
But, then you knew this, so why am I telling you what you already knew.
In the made-up confed he had (and exercised) whatever “rights” fancied him. He wasn’t exactly known for obeying the law ;-)