Interaction between pkdown and `\AND` in JSS articles

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When creating a package website using pkgdown for a package that contains a JSS vignette which has authors arranged using \AND, the following issue comes up:

First a minimal package where everything works as expected:

usethis::create_package("rticles398")
usethis::use_mit_license()
rmarkdown::draft("vignettes.Rmd", template = "jss", package = "rticles",
                 edit = FALSE)

rmd <- readLines("vignettes/vignettes.Rmd")
ind <- grep("---", rmd)[2L]
rmd <- c(
   rmd[seq_len(ind - 1L)],
   "pkgdown:",
   "  as_is: true",
   "  extension: pdf",
   "vignette: >",
   "  %\\VignetteIndexEntry{A Capitalized Title}",
   "  %\\VignetteEngine{knitr::rmarkdown}",
   "  %\\VignetteEncoding{UTF-8}",
   rmd[seq.int(ind, length(rmd))]
)
write(rmd, file = "vignettes/vignettes.Rmd")

usethis:::use_dependency("knitr", "Suggests")
usethis:::use_dependency("rmarkdown", "Suggests")
usethis:::use_dependency("rticles", "Suggests")
usethis:::use_description_field("VignetteBuilder", "knitr", overwrite = TRUE)
usethis:::use_git_ignore("inst/doc")

devtools::build_vignettes()
# --> all fine
pkgdown::build_site()
# --> all fine

If, however the affiliation containing the \AND also contains an address, as

rmd <- readLines("vignettes/vignettes.Rmd")
ind <- grep("\\AND", rmd)[1L]
rmd <- c(
   rmd[seq_len(ind + 1L)],
   "    address: |",
   "      | First line",
   "      | Second line",
   rmd[seq.int(ind + 2L, length(rmd))]
)
write(rmd, file = "vignettes/vignettes.Rmd")

devtools::build_vignettes()
# --> all fine
pkgdown::build_site()
#> Error : Failed to render RMarkdown
#> * ! Undefined control sequence.
#> * \@Address ...~\\ Second Author\\ Affiliation \AND
#> *                                                   \\ First line\\ Second lin...
#> * l.124 \end{document}
#> *
#> * Error : LaTeX failed to compile /some/dir/rticles398/docs/articles/vignettes.tex. See https://yihui.org/tinytex/r/#debugging for debugging tips. See vignettes.log for more info.

There is a fix for this: If an affilliation2 is added in addition to the offending affiliation, which does not contain the the \AND, the problem goes away.

1. Is this intentional?
2. If so, I feel adding a remark somewhere, outlining the fix above, would be helpful, as it took me quite some time to get there.

R version 4.0.4 (2021-02-15)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Big Sur 10.16

Locale: en_US.UTF-8 / en_US.UTF-8 / en_US.UTF-8 / C / en_US.UTF-8 / en_US.UTF-8

Package version:
  digest_0.6.27   evaluate_0.14   glue_1.4.2      graphics_4.0.4
  grDevices_4.0.4 highr_0.9       htmltools_0.4.0 jsonlite_1.7.2
  knitr_1.33      magrittr_2.0.1  markdown_1.1    methods_4.0.4
  mime_0.10       Rcpp_1.0.6      rlang_0.4.11    rmarkdown_2.6
  rticles_0.19    stats_4.0.4     stringi_1.5.3   stringr_1.4.0
  tinytex_0.31    tools_4.0.4     utils_4.0.4     xfun_0.22
  yaml_2.2.1

Start by reproducing the example in vignettes/vignettes.Rmd, running devtools::build_vignettes() and pkgdown::build_site(), then inspect the generated docs/articles/vignettes.tex and its LaTeX error. Determine whether an affiliation containing \AND and a multiline address should build successfully; done means the failing case is fixed or the intentional workaround is documented.