Oh I like this idea!
Also, why not have the SRV radar show a colored thing for lifeforms, like it does for geo?
Because it's not showing the geo at all, it's showing the mats that are attached to the geo features. The old style Horizons bio that have mats do indeed show up on the SRV scanner because of the mats. Personally I think there should be a change of function, if I am looking to shoot stuff, mats for instance, that function should work for the SRV in combat mode, if I am looking analyse bio when I am in analysis mode it should show bio locations. Whether that can be done or not I don't know, since the scanner doesn't actually show geo maybe that is because the geo is procedurally generated and the it wouldn't work for bio because of that? I am not sure exactly how the SRV scanner is coded so that would have to be up to the devs to work out whether or not it could be done!