For the sake of making sure everyone is on the same page.
When referring to GI for outdoor environments, skylight and bounced light from the sun are both considered as GI, though they both simulated using different tech. Skylight can already be made to be dynamic except for the shadows/occlusion. When used with atmospheric fog, the sky will change based on sun location, and the skylight capture(if setup to update dynamically) will reflect the change in sky color. (Dynamic skylight shadows are in the works and an early version will be in 4.3).
Bounced light for an outdoor scene is nice, and LPV seems to work great for this(it’s the indoor scenes where light leaking causes problems). But it’s not really needed to make an out door scene look great unless there are specific area that really need the extra light.
Also, the argument of whether static or dynamic looks more realistic is referring to two different types of realism.
Static GI will have far more realism when it comes to lighting calculations and visual quality on a static world. But at the same time, is completely unrealistic in world where lighting and/or the environment needs to dynamically moving around.
Dynamic GI will have far more realism when the lighting or the environment is dynamically moving around, but the lighting calculations will be of much lower quality than pre-rendered light maps.