Hey Sotherls, I work on multiple SW environments. Every environment I manage publishes reports immediately, if I had to guess a time I would say that it's easily under 1 second.
The only thing that comes to mind for latency aside from insufficient resources on your NPM box is the report not saving to the reports folder.
Could also depend on the query some larger queries can take an awfully long time to execute. Try seeing 'TOP' 5 and use the 'group by' functions if possible.
You should also consider the amount of resources that you have loading into a single page and the amount of users that concurrently use the platform this may reduce the transaction times.
You should give 'Hubble' a go, to help determine the bottle neck.
Also a reboot of the PPE never hurts
Try checking out the logs iv seen previous environments that give you error logs due to 'long running queries'
ps reportwriter is awesome