@mwebster Hello! Thanks for your questions.
Here is how I've set mine up: For the slide you can turn on the keybend on the Sylphyo (which will act like a pitch bend + and set it in SWAM software to your desired bend effect (I find that + and - 3 works well for what I like, but you might want more or less). You can also set the keybend in Sylphyo to send out a midi CC message which can then be mapped to any parameter you want in SWAM, but for my purposes I've found that leaving it on pitch bend works well.
For the mute, I use the slider to control which mute is engaged and the roll movement to control the position of th mute. This works well and is quite natural (at least when looking at the screen to determine the roll and the mute position).
Let me know if this is helpful for you! I'm working also on a little demo of SWAM with Sylphyo.