One way hams handle gain and noise issues (on the lower frequency bands in particular) is to phase antennas. Frequently this involves a two or even more antennas some significant portion of a wavelength away from each other and use various switches and phasing lines to yield several different patterns.
It occurs to me that if the output of two SCUs were to be added together with each antenna connected to a different SCU, one could do all this phasing stuff in the digital domain. That it should be pretty simple (always easy for a user to say) to provide an addition function with a controllable phase offset that could be adjusted between +/- 180 degrees. Thus with the correct antenna setup one could effectively adjust intuitive for the best signal peaking or adjust for maximum nulling of a noise source/QRMing signal.
Unlike a phased antenna this wouldn't help on transmit, but it could be a very handy receive feature.
This thought isn't entirely my own and was inspired by a discussion about things that could be done with multiple sampled data streams. Most of which seemed very complex, but this basic feature seems like something that may not be too difficult to implement for the models that have dual SCUs.