Welcome Josh and Ride On with Zwift. You can use only the iPad to ride your Keiser on Zwift with the converter. I use an iPad to drive the main program using Bluetooth. I also use my iPhone to use the Zwift Companion app as well, as they allow you two different looks and allow you to communicate a bit more freely during the ride. Some lessons learned.
IPad with Zwift program loaded should be the only device in Bluetooth mode anywhere near at beginning of your ride. To remove interference, my iPhone has Bluetooth disabled, also in airplane mode and on the same wifi signal as the iPad.
If using a heart rate monitor as well, allow it to connect with Keiser bike first before you open the Zwift program on iPad.
Once you open the Zwift program you will have Power, Cadence and HR all connected; make sure your converter is updated using the Keiser Converter DSU app. This will help battery life which is not overly good so make sure to order spare batteries a head of time.
Until you get things worked out, you can have signal dropouts which can be frustrating. HR monitors will intermittently lose signal but not for long and does not impact the ride.
Get a fan, some music in the room and enjoy.