Thanks!
The batch is too small and the window is way too small. Go with the default window of 50,000 and a batch of 1,000,000.
Download will always end up waiting on validation even when you are bandwidth limited, as validation always takes longer, so that conclusion is in erroneous. I would expect 4,000 to significantly slow the run.
No reason to change delay inbound, leave that true.
The node priorities are already true by default.
There is no good reason to remove checkpoints, as doing so is a hard fork. But they only take a couple of minutes to doubly-validate, so it's not significant.
The build is missing sse4/avx2 hardware optimization. Not significant given shani, but would still be net positive.
Only question... what's the measured bandwidth?