So far, after owning the car for 19 years I had to bleed the cooling system just once. After I installed the Alfa engine. So I am not too concerned about having to take out the front floor for bleeding the system.
I have to get the floor out anyway to repair the lighting system, so that would be a good time to change this as well. Guess I will guide the hose through the floor and put a small collector tank there (assuming there is a pressure releave at the radiator) to catch eventual spilling. This way I could use this hose as well if I should need to bleed the system.
Unless the radiator was changed for something different when the Alfa V6 was installed, the standard Murena radiator does not have any pressure relief fitted. It simply has the top and bottom inlet and outlet connections plus that bleed point at the top right.
Also I may have been wrong in my previous posting because there is some circulation back to the header tank via that bleed hose when the engine is running as can be seen if you watch it carefully. So if you disconnect it entirely I would monitor things carefully until you are sure it is not having any detrimental effect.
Roy