Stabilizing private islands

Called concierge services today after averaging 4 crashed a day. First concierge said we never crashed. Call back. Second one says he sees all of the crashes but they are all caused by a variety of things. One was the bottleneck of people rezzing at the same time to attend events. I mentioned having several rez points to combat this issue. He told me how to do that using estate tools. Supposedly folks won't all rez on each other heads in one spot anymore. But we crashed again after I established two extra rez areas so I'm back where I started. Are there any other solutions? the unstability of the island is becoming a major hindrance.