In theory if the condenser condensed 100% of the vapour produced in the boiler then there would be no pressure and the vent would not be needed
Its sile purpose is a form of pressure release when the output valve is shut.It makes sense to have it as far from the vapour as possable.......the coldest end of the condenser.
From memory Harrys original crossflow condenser may hav had lots more pipes in it.They may have been 3/8" too