Jamba addon has a subsection of commands called Jamba-Follow. You can configure Jamba within warcraft by pressing escape, selecting interface, going to the addons tab, and then selecting the component of Jamba you'd like to configure.

You can have Jamba warn you, via guildchat/specified channel/party chat/raid warning when follow breaks, you can configure a custom phrase; I use "Slow down, you're going too fast".

Jamba can be set to strobe auto follow every "x" seconds. It can be set to auto resume follow once combat ends. If you want to auto follow and not have to worry about it much, this is a great option. I used this for the longest time, but recently have had times where I'd prefer the alts remain where they're parked (example the temple event in ZF), rather then follow the main. Still its easy to toggle on one and then broadcast the settings to all of the others via a mouse click.