This wouldn't work in a mono setup (unless you had a simple 2 channel mixer, or another pedal to combine 2 channels, like another H9 or similar), but with the new Wet Dry Routing mode the Input Swell will only affect the Wet channel, the dry channel stays in tact on the other side. So…. like I said, it's a slightly annoying workaround, but maybe there's something there you could work with? Do you have other pedals that will combine Stereo in and output a combined mono signal?
With a stereo setup though, you can get what you want, b/c Wet Dry Routing mode allows you to save your presets in either Wet Dry configuration OR in regular Stereo mode.