To the degree it can run locally an internet connection will not matter. Maybe there is a dependency on the internet to collect user data from the user's computers. That is necessary latency. Internet network latency due to dashboard application execution is not necessary.
I am not saying that Internet network latency due to dashboard execution matters. If it doesn't matter then there is no point optimizing for one or other sort latency until it does. If it does matter then picking one over the other suggests an architectural design issue.
Mostly it wouldn't matter. This would basically reflect the preference of SPA vs non-SPA sites or Desktop vs Web app. In both cases the trade-off is similar. A big one time download vs small added delays in each request (ignoring the network dependency in each). Of course this preference comes at the bottom of the priority list.
