Use of Aux bus routing

Let me ask the question what is the intended operation of the aux bus and master bus in Synfire ?

In Cubase it is perfectly clear how the routing works for mixing/mastering and hope that the routing in Synfire can also be done with a mixing (aux) bus. ( but with 1 master plug in ? ) and mastering bus ( with 1 mastering plug in ?).

Would be nicer if more than 1 aux bus can be used in Synfire. If I use an aux bus for a send effect, then I'm an aux bus short for a mixing bus.

Is the aux bus in Synfire for a send effect (a reverb) only meant for all instruments at once to give a reverb? In short it is not clear to me the intended operation of the aux and master bus in Synfire.
Would be handy if you can mix and master your own arrangement in Synfire without having to do it in Cubase. 

Can't a simpler mixer be added in Synfire a la Cubase, Logic etc ?
A mixer screen of its own to which aux buses and a master bus can be added. 
That would be better than the current configuration of an aux bus and master bus in Synfire, because there is nothing to see visually. 

doubling post

Thanks, I know it's not a priority, but it would be userfriendly if there was a mixer tab, where it could be seen visually.
Have a feeling that this is not too difficult and Logic or Cubase are the examples to get a simplified mixer  
 

One aux bus for a reverb on all instruments is good and necessary, but needed is also a mixbus where all instruments are routed into, in order to do some mixing further on the instruments
Also the functionality to add groupbusses , what also can be routed to a mix bus. 
This mixbus is routed to the master bus where multiple master effects can inserted for the final mix