11.52.3 Can you answer these questions?

11.52.3.1 Itemize item markings are not scaling when using beamerposter+fontspec (in XeLaTeX)

https://tex.stackexchange.com/landing/r/digest?cta=question&id=749177

The following minimal working example shows that the \times used as item marker scales with the rest of the text (when using beamerposter without fontspec): 
\documentclass[final]{beamer} 
\usepackage[... 
[xetex] [fontspec] [beamerposter]
 

asked by DCTLib https://tex.stackexchange.com/landing/r/digest?cta=user&id=28509 Score of 1

11.52.3.2 Increase letterspacing only for math

https://tex.stackexchange.com/landing/r/digest?cta=question&id=748906

We use Fira Sans Math as a math font, which works well, but equations look a bit "dense". I would love to increase letterspacing for math in general, by a tiny bit. 
We tried \usepackage[... 
[math-mode] [luatex] [microtype] [letterspacing]
 

asked by Philippp https://tex.stackexchange.com/landing/r/digest?cta=user&id=17422 Score of 1

11.52.3.3 How to balance vertical spacing across columns when using tcolorbox inside multicols?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=749105

I've been having trouble with balancing the vertical space across columns between tcolorboxes. 
I'm using the multicols environment along with tcolorbox to display definitions in two columns. Here's a ... 
[spacing] [tcolorbox] [multicol] [vertical-spacing] [vertical]
 

asked by tesseract0 https://tex.stackexchange.com/landing/r/digest?cta=user&id=409308 Score of 1