Originally Posted by
ubiest
As long as OP can exit and reenter the Schengen Area, I don’t see why she could not go through exit passport control, stay at Velázquez lounge, and then return via arrival passport control back to the M gates. This would be allow better time management than having to leave Dalí and take the transit to T4S IMO.
While maybe technically possible but you would have to go all the way back to T4main and back regardless as there's no Schengen security. Basically once you're through passport control the only way you can go is to T4main. And the difference between Dalí and Velázquez really isn't that massive.