Thanks for the blockmaxweight tip - I was using the old suggestions.

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Please ignore the bits that suggest setting and tuning a blockmaxsize value. The blockmaxsize parameter has been deprecated in favor of the blockmaxweight parameter, which you should set to a suggested maximum of 3950000.

If you have a system with a reasonably fast CPU (one with a base clock of at least 2.4 GHz) and at least 4 GB of RAM, you may want to try out jtoomim's 1mb_segwit fork, if you aren't already, which promises better overall performance and reward fairness. Using PyPy to run 1mb_segwit is highly recommended for maximum performance.
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