I have been trying the tufte handbook style on RStudio using the skeleton.Rmd script. It works ok excepting the [@R-base] side citation that sets cursive for the rest of document probably because of bad format in reference. Other than that, it works nicely. As I am not very experienced in TeX output in Rmarkdown, I would like to know if the Tufte format is necessarily linked to LaTeX and xelatex engine, or using the ConText engine can manage it and I could use ConText engine in Quarto to generate Tufte formatted document with Tex output. I'm using Quarto with context engine to write a technical book and that option would be so nice. Thanks for help!
The tufte styles use the tufte LaTeX package; they cannot be used with ConTeXt.
There are very few (if any) predefined styles for ConTeXt, so you'd have to build this yourself. The only help I can offer is to link this ConTeXt template, which might contain a few pointers on how to build a suitable ConTeXt pandoc template.