I wouldnt recommend using the SkyTest SDM either. Back when I applied for the DFS, I tried to use SkyTest to get familiar with the test. I didnt manage to find a single opposite conflict while practicing, so I was really stressed out going into the test.
When I was actually being tested, they had a 45 minute instruction for the test that made everything very clear. I found like 6-8 opposite conflicts during the actual test.
Also I had my FEAST II in April and I didnt have to do the SDM anymore. They now have something called Multipass that, if I recall correctly, completely replaced the SDM