Aside from the fact that I'm more in the roleplayer camp, I have to admit I can't even imagine a useful way to use spreadsheets in Stellaris. I mean, most of the game's math is based on simple addition and subtraction, with the occasional multiplier. If I want to know where to build a Power Hub, I just look at the total energy production.
And for keeping track of things - if you really want to do that, there's Notepad or OneNote for that. Why use Excel? Do people really find that easier?