This is pointless - you need to read a bit more than a few paragraphs. Vessels are categorised, masters are required to effect rescue or explain why not. We all rely on each other for our safety at sea.
You are claiming your greater understanding of the guidance gives you the benefit of a "legal" argument. When in reality, you are simply applying your far-right interpretation of that guidance, supported by far-right web sites.
It still makes no difference to the category of the vessel whether they can, or will effect a rescue, or the treatment of those rescued afterwards.
The rescue ship is free to choose to transport those rescued to a convenient point of safety, in their opinion, not somewhere dictated by the guidance, unless, of course, there is a medical emergency. But as you say, the master is still free to act as they see fit. Otherwise lifeboats, helicopters etc would simply land those rescued on the nearest bit of land.
A 'normal' freight ship will not divert its course, merely to land rescued seafarers, but will continue to its original destination to land those rescued, unless there is a medical reason for greater urgency.
If the chosen point of safety refuses to allow those rescued access to the point of safety, they are acting unilaterally, and against humane principles.
Italy argued, (their far-right minister decided) that their reason for refusing access for the Aquarius is because the Aquarius and other such ships were merely taxis for traffickers, which of course is nonsense. Which you have supported by your pseudo legal babble. That is the only point at which the category of the vessel comes into the discussion.
The reason why the rescued migrants have been landed in Italy is because there is a reception area there for them, and for expeditiously allowing the rescuers to return to the SAR zone.
While the Aquarius and other boats were en route to Spain another 200 migrants drowned!
If other ships choose to avoid the SAR zone, they cannot effect a rescue.
Additionally, some ships are reporting the presence of migrant boats but not effecting a rescue.