Hmm,

   https://www.percona.com/blog/optimizing-innodb-for-creating-30000-tables-and-nothing-else/

reports using libeatmydata. Starting mysqld as:

  sudo -u mysql eatmydata mysqld &

(after creating /var/run/mysqld with user:group mysql.mysql)
and running and it completes in not ~14000 seconds but ~411.

Mysql

   224 passed in 411.67 second

with load average in the mid 2's not mid 4's. Still have I/O waits in the 80/90 on some cpus
(2 core 2 thread).

For comparison postgresql:

   456 passed in 507.34 seconds

Will see if mysqltuner can help.