Just a comment here on the performance writing on a single stream:
We wrote 3700000 key-values on the root stream with the following format:
key: random uuid
value: 100byte hex
So: 1 stream -> n keys -> 1 entry per key
When you do a liststreamkeyitems with default parameters you directly get back the result.
When you do a liststreamkeys with default parameters you the node hangs with 100% CPU and does not return even after minutes.
I saw that the default of count is MAX_INT. Maybe this is a bad idea since the function performes still great with low count values.