I'm confused about the Dashboard

I just signed up, mostly to try out plugins and themes to see if this is a better solution than what WooThemes & WooCommerce have become.

I don't understand the Dashboard, however... do I have to install the Dashboard on every site I design for clients in order for them to maintain any WPMUDev plugins I may use for them, even if I don't continue to maintain their site after it's completed?

I've never used Multisite, ever, there was never a need, so all of my sites and my client sites are standalone. Even the membership based site I'm considering building would be standalone.

So am I correct in thinking that I'd have to install the Dashboard on anywhere between 30-50 different websites?