What version of MySQL and/or MariaDB do you recommend for the latest versions of Joomla (3.9.8) and JMS (1.3.75)?

I am running my JMS site on MySQL 5.6, but WHM is asking me to upgrade MySQL and is recommending upgrading to MySQL 10 or MariaDB.

I note that MariaDB says that the following versions of MySQL are compatible with the corresponding versions of MariaDB:

MySQL 5.5 = MariaDB 5.5
MySQL 5.6 = MariaDB 10.1
MySQL 5.7 = MariaDB 10.2

Is JMS 1.3.75 compatible with MariaDB 10.1?

I note this info from Michael Babker about testing of the Joomla framework with MariaDB:

"For what it's worth in the Joomla Framework's Database repo (github.com/joomla-framework/database) I added MariaDB to the testing environment so it is now proactively tested against using the same test code as the MySQL integration."

And also note this github thread discussing why MariaDB is not yet officially supported by Joomla.

MariaDB and MySQL is identical and does not change anything.
JMS, like Joomla, uses the PHP MySQLi driver to access the DB.

If you don't want to take any risk, continue using MySQL.