I also prefer to use more AUD than SBD...Depending on the venue, I may roll the bass off a few db on the SBD source (not sure the mixpad has this)...but "matrix on the fly" is really hit or miss...
Ideally you should record each source independently - at the same sample rate - and matrix them later on your computer. Then you can play with the timing of each souce - which makes a big difference, as well as the blend...
I've been told that you cant matrix resampled sources...? Like: you cant make a 48>44.1 source work with a source that was originally sampled at 44.1