使用rhandsontable时，如何停止hot_to_r在下载时添加列

install.packages("rhandsontable")
library(rhandsontable)

data <- data.frame(A = c(1, 2, 3), B = c(4, 5, 6))
hot <- rhandsontable(data)

data <- hot_to_r(hot)

custom_button <- htmltools::tags$button(
  id = "stop_adding_columns",
  class = "btn btn-primary",
  "停止添加列"
)

hot$settings$buttons$custom <- list(
  html = custom_button,
  callback = htmlwidgets::JS(
    "function(hot) {
      var btn = document.getElementById('stop_adding_columns');
      btn.addEventListener('click', function() {
        hot.updateSettings({
          colHeaders: true,
          columns: [
            {data: 'A', type: 'numeric'},
            {data: 'B', type: 'numeric'}
          ]
        });
      });
    }"
  )
)

hot