Kind of not related, and I might be wrong but:

Aren't single research techs supposed to be rectangular and multi-research techs oval-shaped? Or am I just assuming things?

I can't seem to figure out otherwise why some multi-research techs are a mixture of both.

Those are just XML typos.  Don't worry about them.  There is no deep mystery; it's just a typo (or several).

Stardock has no "GC3 tree of buildables" tree editor, so they use one big fat Excel file.  Humans are poor at manually enforcing tree-wide consistency from raw source code.  Hence we go to such lengths to build compilers (including TeX/LaTeX) and application-specific editors (CAD, Visio/PowerPoint/graphics, spreadsheets, home/online tax prep), and leverage them to achieve great things.  We make spell-checkers, too

Maybe after GC3 stabilizes, Stardock will retroactively develop a tree-editor, use it to fully express the power of their XML scripting engine, and build DLCs, GC4, and other games on top of it.  For now, it's lower priority than the new graphics engine, battle viewer, and AI, which are the things they brag/wow about in dev streams.

Updated original post with a few more.

Another thing I noticed, when you research the radioactive mastery tech, you end up getting the 50% research bonus on toxic worlds and vice versa with the radioactive mastery tech (only checked that for the YOR). So not so much typo, but also something typically human...