Today I spent a few hours trying to run it on a pi zero w. I’m using a pHAT DAC and a generic hdma monitor. Wiring set to dummies. I keep getting the Zynthian “Error” screen. Wifi broadcasts zynthianos and I have to enter the password two times before I can connect my iPhone to the network. Zynthian.local will not connect and times out. Prior to trying the Zero, I put the same sd card in a Rpi3 using the same configuration settings and same pHAT DAC and monitor. It boots and displays the Zynthian gui with no “Error” screen.The rpi3 broadcasts zynthianos and I can connect to the Zynthian configuration tool. I haven’t tested out all functions on the rpi3, but most of the things I’ve tried worked. As you mentioned sound fonts are missing and Mod Ui needs work. I tried to load the Pure Data Engine but it gets stuck in an endless loop and freezes the system. I will continue with further tests in the next few days to see if I can get Zynthian working on the Zero W.