Can you remember us the cPanel issue that you seems have encountered.
All I can tell you is that cPanel itself exists with full priivileges and does not require anymore actions from the hosting provider to share the MySQL tables.
We know at least one hosting company (
www.hostgator.com) that provide cPanel with shared hosting that does not require any additional support from the hosting company.
JMS Multisites has no issue with cPanel and you have several video that show how it works with cPanel - see the tutorial video CP-xx
www.jms2win.com/tutorial
If you are using your own server, up to you to configure you cPanel correctly and provide the correct permissions.