Mobile AddOn license for public mobile device access?

I volunteer at a not-for-profit advice organisation.

We are considering purchasing TeamViewer as a way to help members of the public during the Coronavirus Pandemic who need to apply on-line for benefits or for other government support.

We are a team of less than 15 people who will only use this occasionally, and our use case is that we will ask the client to download QuickConnect to their mobile or tablet so that we can see their screen and guide them through the process of making their on-line application for assistance.

I am aware of not-for-profit discount pricing and we think a premium license with maybe one additional Channel AddOn would be sufficient for our need.

However I canot figure out if we need the Mobile AddOn for our use case. No-one within our organisation will be using. a mobile device, but we do want to be able to connect to the mobile devices of our clients.

Can anyone please advise whether the Mobile AddOn would be necessary for us?

Many thanks!