At first, I had other devices connected (and operating normally): Celestron Nexstar (CGEM), ATIK 314L CCD, ZWO/ASI 120MM (guide camera), and Moonlite Focuser. After extended time trying to sort this out at the telescope over a few nights, I moved indoors and setup using a simulated telescope, simulated CCD, and the ASI filter wheel.
The EFW appears to connect to my RPi, but INDI isn't able to see it for some reason.
matted@AstroShed:/dev/bus/usb/001$ lsusb
Bus 001 Device 006: ID 046d:c315 Logitech, Inc. Classic Keyboard 200
Bus 001 Device 008: ID 03c3:1f01
Bus 001 Device 007: ID 046d:c01a Logitech, Inc. M-BQ85 Optical Wheel Mouse
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. SMC9514 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub