I think so, although it might depend on what you mean by "seamlessly." : ) The reason I say that is because if you switch to a new patch while sounds are still playing under the previous patch, the transition may or may not be seamless depending on differences between the old patch settings and the new patch settings. I think this has been mentioned in the other thread you started.
I'm answering in this thread because you've asked about using a DAW, so that's what I'll address here.
There are two possible ways to approach this. The MX synths let you set up and save a performance, which is where each of the 16 parts can be used for splitting and layering the keyboard, or as alternate sounds that you can switch between without having to switch to a new performance. Unfortunately, the setting up process isn't very easy to do on the synth itself due to the nature of the display and the menu system, but there are two software programs that help, one free (Vycro MX) and the other not (from John Melas).
if you set up your voices, splits, and layers as performances, you can select the desired performance from your DAW by sending the appropriate Bank Select and Program Change values to the MX, similar to choosing a single voice. This is because the 128 user performances have their own bank number, and each program in that bank corresponds to one of the 128 user performance setups.
The other approach is to just send Bank Select and Program Change values for the individual voices, on whichever channels you want to use them on.