Theres actually not a whole ton of difference between not being connected to a robot and being connected to a robot. Its all just done over UDP, and because of how the DS protocol works it is just sending the normal packets at the normal rate, and then using if a reply was received to detect if a robot is connected or not. At the same time, it keeps attempting a TCP connection to what should be the FMS, to know if there is an FMS connected. So the difference between connected and disconnected isn’t much. And as said above me, theres actually a lot of work being done to make everything work and be responsive on the field. Holding a 20ms timer requires turning up the windows timer resolution, which will increase battery usage. A web page doesn’t actually have to do anything when idle, unlike when the DS is idle, where it still has to do work.
As for installation, you don’t need the full labview install to install the DS. The FRC Game Tools package includes the runtime and everything needed to install the full DS. Now if you have installed full LabVIEW, is probably not super easy to remove it, rather then just removing it all, and then just installing the game tools by itself.