No. Currently we can’t revoke set/show rules in Typst. But it’s a planned feature: Related issue, Typst Roadmap
If you want to apply two different styles to the same element, you can encapsulate the element with specific styles into a function, for example:
#let styled-text(..args) = {
set text(font: "Buenard")
text(..args)
}
#styled-text("123", size: 10pt)
But I guess there’s probably no way to encapsulate the default style into a function, especially when you applied a show
rule.