There is no legitimate reason to structure the operating entities as described - just more of the shell game, MMEX as usual.
The normal process for a business like this is to establish a joint venture (JV), and a special purpose vehicle (SPV), or "orphan company" - the SPV owns the project from construction through start-up phase, and to the point that the project financing has been paid back to the JV, through the SPV's operating profits - this includes the debt, and interest. Then the SPV sells the interest to an operating company, at is dissolved.
A topping unit, in any of its forms would be integral to a complete, complex refinery - there is no legitimate reason to run a distillation unit in a stand-alone fashion, as it is guaranteed to always lose money.
This is just more MMEX hocus-pocus, and further reflects MMEX's complete and total lack of the refinery sector.