TL;DR
The game should make clear to the player that the Spidertron always has innate radar coverage of the area around it.What?
A line could be added mentioning something like "automatically reveals the map around itself" to the research description (so the player knows before they already have one), and possibly also the item description & first Spidertron Tips & Tricks entry.Why?
Particularly in Space Age where Tanks also have equipment grid and can also be driven remotely from other planets, one of the biggest advantages that Spidertrons have is that they do not need to be driven in areas you already have radar coverage, but can go anywhere on the planet will full vision, even if your base collapses and all your radars shut down.However, other than a "hint" of the recipe requiring two Radars, there does not appear to be any indication in-game that Spidertrons have this powerful ability. It is quite possible that a player who first tries out remotely driving the Tank and discovers they cannot see where they are going when outside of Radar coverage, will learn from that mistake and never attempt to drive a Spidertron outside of the Radar coverage of their base, and thus never discover this feature. (This almost happened to me, if I hadn't learned about the feature online from other users)