To DEVs
Hi guys - hope you are enjoying the ride (remember to keep any limbs you wish to retain inside the car at all times)

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Nodes - I think you have too few, and poorly distributed.
I think that the high apparent orphan problem in at least the early hours is a symptom, and the fast blocks and low difficulties are exacerbating the issue.
Think about it in non-rocket scientist terms. If your block time is 120 secs, 100 extra ms here or there is a relative low percentage. Not so when blocks are seconds. When a new block is reported this promulgates to the nodes, and then by LongPoll outwards, then mining stops until reception of the next block. Even in processing terms, if your latency is poor, your miners are marking time longer. Things get more expensive when it is about presenting solutions, because the window for multiple acceptances is wider, and thus there are more orphans.
I get pings of between 270 and 370ms to your four nodes, and haven't seen a confirmed block (numerous unpaid orphans, though).
One litmus test is to see how many non-US users are mining successfully. Anybody?
How about the ping times to your nodes?