kableExtra addfootnote general spanning multiple lines with PDF (LaTeX) output

Question

Problem

Code

# Toy Data
ID <- c(paste("G0", as.character(1:9), sep = ""),"G10","G11","Mean")
V1 <- c(10.06,11.06,12.06,13.06,14.06,15.06,16.06,17.07,18.07,19.07,6.88,13.86)
V2 <- c(0.21,0.03,0.09,0.03,0.09,0.03,0.09,0.03,0.09,0.21,0.31,NA)
tbl <- data.frame(ID, V1, V1, V2, V1, V2, V1, V2, V2)
colnames(tbl) <- c('ID','Get. \\%','Get. \\%','K','Get. \\%','K','Get. \\%','K','P')

# Specify kable NA value and load kableExtra
options(knitr.kable.NA = '--')
require(kableExtra)

# Generate table for PDF output (LaTeX)
kbl(tbl, format = 'latex', align = 'l', booktabs = T, escape = F, digits = 2,
    linesep = "", caption = "This is a table caption.") %>%
  add_header_above(c(" ", "AB", "BP" = 2, "CK" = 2, "JAM" = 2, ""), bold = T) %>%
  column_spec(1, width = '1.15cm') %>%
  row_spec(11, hline_after = T) %>%
  row_spec(12, bold = T) %>%
  kable_styling(position = "center", latex_options = "hold_position") %>%
  footnote(general_title = "Note.", footnote_as_chunk = T, 
           general = "Relatively long footnote that I would like to span 
                     a couple of lines. Relatively long footnote that I
                     would like to span a couple of lines.")

Output

Comments

Issue 1: The output displays 'makecell[1]' in the footnote, which I obviously do not want included. Adding the argument escape = T did not resolve this problem as I expected it might have.

N.B. By setting footnote_as_chunk = F, this issue was resolved, but with the unwanted effect of introducing a line break before the caption starts. This is demonstrated by Peter's answer below.

Issue 2 The footnote does not want to be constrained to the length of the table. I suppose one might be able to manually add line breaks in the footnote string, but this seems like tedious work-around, and I'm hoping there is a method for achieving this more efficiently. The documentation shows (see Table 4, p. 25) an example of how one might circumvent this problem, but the code is absent.

EDIT: This issue (#2) was resolved by setting threeparttable = T when calling kbl.

Compiling with pdflatex or xelatex does not seem to make any difference. Any insight would be much appreciated.

Answer 1

Try this:

library(kableExtra)
library(magrittr)

kbl(tbl, 
    format = 'latex',
    longtable = TRUE,
    align = 'l', 
    booktabs = T, 
    escape = F, 
    digits = 2,
    linesep = "", 
    caption = "This is a table caption.") %>%
  add_header_above(c(" ", "AB", "BP" = 2, "CK" = 2, "JAM" = 2, ""), bold = T) %>%
  column_spec(1, width = '1.15cm') %>%
  row_spec(11, hline_after = T) %>%
  row_spec(12, bold = T) %>%
  kable_styling(position = "center", latex_options = "hold_position", full_width = FALSE) %>%
  footnote(general_title = "Note.", 
           footnote_as_chunk = TRUE,
           threeparttable = TRUE,
           general = "Relatively long footnote that I would like to span a couple of lines. Relatively long footnote that I would like to span a couple of lines.")

With footnote_as_chunk = TRUE using the "general" footnote option "Note." and the "Footnote...." text start on the same line. As in this example, image below.