Sure this makes sence. We will have to think how we could implement this feature.

Meanwhile you can use the following workaround:
scanned server list is stored inside vnc manager configuration xml file. You can set location of this file via
Tools->Options->Advanced->Configuration Path setting.

So if you set this property to shared location, all users will be able to share scanned servers list. But as drawback, they will be sharing all configuration settings too.

Actually we do that on my company.

On Tools > Options > Advanced

We have the "Configuration path" and "Server List Path" configurated to a network share.

Altough (since the VNC Manager only reads the list when loging in) to avoid problems of writing over others modifications, only one of the users has security set to write, while all others have "read only". So one person is elected as the one to update/configure the list and settings. This is also usefull cause of the external tools configuration file.

Hope i have helped in some way, by sharing this to you.