FROM THE f5 WEBSITE Dated 10/28/14
"F5 will soon provide an upgrade of BIG-IP Edge Client for Mac OS X 10.10 (Yosemite) for BIG-IP APM versions: 11.6.0, 11.5.1, 11.5.0, 11.4.1, 11.4.0, 11.2.1, and 10.2.4. The FirePass controller is not and will not be supported."
From that statement alone it seems the decision is with f5 and not Apple to fix this. Our company is about a 50/50 mix of Macs and PCs so it has created big problems for us as well. We are nearing the need to upgrade our BIG-IP APM and it looks as though we will be switching to a different firewall solution going forward.
The only solution that has worked for me is to run the WIN version of the Edge Client. I do this by using VMWARE Fusion or Paralells. I suppose you could dual boot your Mac into WIndows as well, but I haven't tried it. Of course, this isn't ideal and requires me to work in Windows when I don't *need* to, but it allows me to be mobile and not be tied to my office.
Hope that helps.