Orange cannot waiver sanctions, nor release frozen funds ... even after signing the MoU with Iranians he clarified that those funds will not be coming from the US.
The president has limited ability to waive some sanctions... primarily the previous EO's or others designated to be under executive discretion.
It is instead a muleta being waived by orange to color something he cannot deliver. And, then blame it on congress. It becomes worse yet... if he loses control over the house and congress in midterms. This isn't new, even under JCPOA Obama bypassed congressional appropriation to release some funds.
In this case they didn't even arrive at that stage... even sanctions relief has to go through congress... the president can only lift some sanctions and temporarily.
To use the bullfighting terminology again... orange being the metador waiving the muleta to direct negotiations and then simply step aside. The souther corridor simply couldn't have been