This is great. I appreciate the effort put into this. We can now switch the grid to Comic Sans which makes it infinitely better. 😉
If I may make a couple of suggestions based on trying to select a font face that works for me.
1. I think there needs to be an option to control the size of the font selected, and for me specifically in the grid. I find switching to some of the fonts specifically designed for UI/UX are just too small to read. For reference, I am running 2560x1440 on my screen. I switched to Segoe UI for example, and it is just a little too small. It seems to match the size of the display font in the Explorer window, but the use is just a little different in the grid and interacting with the extra content in the grid. Same goes for OpenSans which was an alternate go to for good rendition on screen and readability.
2. Some ability to control the spacing of the grid would be helpful as well. A little more space between the rows would assist in readability, but needs to be in proportion to the font size selected and the character height.
3. The task list and variable pallets would benefit from the same font size controls; in my case increasing by a point or 2.