Yeah, I’ve got beta 2 on my laptop, and I’m able to launch our project. Seems to mostly work other than occasional drawing glitches, likely caused by the conversion of UIKit drawing to metal somehow not playing nicely with UE4s rendering. I’d holding off on my main machine also, but will keep loading the betas on my laptop out of curiosity.
On the bright side, overall, El Cap seems more stable and feature complete than Yosemite and Mavericks were in beta, so that’s promising.