For sure the two outlet pipes in the “bell” are mounted this (stock) way to achieve a spin of gas within the bell.
If you use an external breather bowl, direction of outlets can be changed to streamline the gases into the bowl.
Remember, we are talking about 750 cm³ to displace air out of the crankcase with each rev of the crankshaft. And to suck 750cm³ air in at every rev.
I would certainly choose a bowl with at least or better more than 750 cm³ to avoid any pumping action, that has to use a space outside the volume of the bowl.
Use the largest possible diameters of connections, pipes, etc. to achieve minimal losses caused by the breather action.
