It's not too hard to collect stale block/share rates and propagation time of messages, I'll build that into the inventory system soon.

Right now the MinCen simulation isn't a good model of mincen yet for the following reasons:

• No MTUs
• No merkle blocks
• Nodes don't adjust peering relationships based on which nodes have best connectivity to miners
• Nodes don't enforce transaction verification before relaying shares
• Transactions aren't being created

When those things are added I can get all of the stats you were simulating before.

Supporting DECOR/GHOST is also on my todo list.