Last I left off, I was trying every incantation of tcpdump I could muster with little success. It was obvious the projector was self assigning an address and simply not broadcasting *anything* to the network. I tried some broad range ping sweeps but between fighting routing tables and the likelihood an embedded device like this would ignore pings (it didn't) I didn't put a lot of effort into this. Instead I sank to the last resort of any hacker worth their weight in flux and I... contacted the manufacturer.
And it worked! A couple of nice folks at Visitech got back to me with some basic questions and gave me a dropbox full of documents!
As suspected the device self assigns an address on reset, 192.168.0.10, how'd my ping sweet not hit that?!? I blame the routing tables.