"US-centric' ... could be good reason for that. In Biz, used to be 'location, location, location' ... with networks and tech now it's still 'last mile, last mile, last mile' - customers/students connectivity upstream.
Rick - Iowa professor - am guessing most students actually in Iowa.
Ops site - a corp - possibly international ... unknown.
Don't think many can get fiber to the desktop.
Once helped a site for a couple of community colleges in Australia hosted on TMD ... site hosted in TMD's data center on coast of USA not the data center in Australia. Why? ... cost more ... significantly more ... to host in Australia. Go figure!!!
Data base tweaks ... highly dependent upon usage and unique to each site.
Example: SCORMs have a checknet thing ... like a ping ... that involves networking. Using other tools in moodle do not.
While one might be talking milliseconds ... they do add up ... takes longer time for a packet to reach destination ... there is a 'time to live' (TTL) built into each packet. If packet doesn't reach destination within milliseconds, packet self destructs. That's in both directions ... moodle to client and client to moodle.
Moodle admins do not control the last mile.
DB tweaks ... number of connections default for both MySQL and MariaDB is 151. If moodle site is basically async, no issues (normally). If, however, a quiz/test has a 1 hour restriction ... opens @ 9am and closes @ 10am ... that will cause a burst of traffic during that hour .... is 151 enough?
InnoDB buffer pool / data size
InnoDB buffer pool instances
If DB server is on same server as code and apache:
Max MySQL memory
Overall possible memory usage with other process
DB runs best when all of it is in memory ... less disk IO.
All this to say, one size/config doesn't fit all!