I thought that a no brainier. Why would you otherwise buy a processor with 20 outputs?
I actually never thought, that having 20CH available could be limiting in any shape or form. And yet - here we are with 22 channels, thinking what to do with 2 spares.
If there is anything really differentiating Alt 32 from Alt16 it is this flexibility of adding channels. with 24 [+4] you should be covered in any scenario [unless you use it really as active crossover and burn 8CH on L-R.]
My latest and greatest plan is to add Flex for CH1&2 [SPDIF] for Surround Back speakers, use crossover function of Flex, add 2 subs to create 2 full range speakers [although my SB play down to 26Hz], and utilize intermediate Bass Management for Rear Heights. Then I have 2 channels free for Front Top [above FW] creating 9.x.9.
More rational part of me knows it is an absolute overkill ;-).