Having the same issue here with kie-workbench 6.2.1-SNAPSHOT. My projects are smaller though. I have 5 projects with ~30 bpmn2 and ~70 short DRL resources in total. The loading time (after you click on the login button) are ridiculous. It is taking almost 5 minutes to show the welcome screen but if I check the dev tools in chrome, I can see that there are still some HTTP request still open. These requests take 15 more minutes to finish!
Could anybody shade some light on what's going on after you login? I tried to check the sources but the amount of repositories you have to clone and the number of projects involved is not helping me at all .