How to format table values rendered with rhandsontable as percentages while retaining and showing full decimal precision?

Edit: see addition at bottom for related but simpler problem

The below R Shiny code, using package rhandsontable, retains full decimal precision via the function row_decimals(). As a next step I am trying to show these values as percentages while retaining full decimal precision. Everything I have tried using format() or custom JavaScript renderer either rounds or truncates the rendered values, which I don't want. Ideally, any values with less than or equal to 2 decimal places are shown with 2 decimals (for example, 0.20, 0.212, 0.2123 shown as 20.00%, 21.20%, and 21.23%, respectively) and any values with greater than 2 decimal places show all decimals (for example, 0.123456789 shown as 12.3456789%). Any recommendations for how to do this? As illustrated in the image below.

Code:

library(shiny)
library(rhandsontable)

# Calculates decimal places for each value in specified column
row_decimals <- function(df, col_name) {
  col <- df[[col_name]]
  n_digits <- sapply(col, function(x) {
    nchar(gsub(".*\\.|^[^.]+$", "", as.character(x)))
  })
  return(n_digits)
}

ui <- fluidPage(
  br(),
  rHandsontableOutput("myTable"),
  br(),
  textOutput("productOutput")
)

server <- function(input, output) {
  values <- reactiveValues(data = data.frame(Values = c(0.5, 0.123456789)))
  
  observeEvent(input$myTable, {values$data <- hot_to_r(input$myTable)})
  
  output$myTable <- renderRHandsontable({
    data <- values$data
    decimals <- row_decimals(data, 'Values')
    data$Values <- mapply(function(x,d){format(x, nsmall = d)},data$Values,decimals)
    rhandsontable(data)
  })
  
  output$productOutput <- renderText({
      product <- as.numeric(values$data$Values[1]) * as.numeric(values$data$Values[2])
      paste("Product of the two rows: ", product)
  })
}

shinyApp(ui = ui, server = server)

Addition to OP: running the below code using rhandsontable, I was unable to get full precision. The problem is relying on hot_to_r(input$hottable_1) to retrieve data from rhandsontable, which is influenced by JavaScript-based display constraints (4 decimal places), leading to a truncated value. In the image below this is resolved by bypassing input$hottable_1 for retrieving values.

Code without full precision:

library(shiny)
library(rhandsontable)

ui <- fluidPage(
  rHandsontableOutput("hottable_1")
)

server <- function(input, output, session) {
  table <- reactiveVal(data.frame(Percent = 1/3))
  
  output$hottable_1 <- renderRHandsontable({
    rhandsontable(table())
  })
  
  observeEvent(input$hottable_1, {
    edited_data <- hot_to_r(input$hottable_1)
    print(paste("Edited data:", edited_data))
  })
}

shinyApp(ui, server)

And in the image below the solution is illustrated in the bottom half:

There's a very nice JavaScript library for numbers formatting, namely d3.format. You can use it for a handsontable with the help of the numeric renderer:

library(shiny)
library(rhandsontable)

ui <- fluidPage(
  tags$head(
    # https://github.com/d3/d3-format
    tags$script(src = "https://cdn.jsdelivr.net/npm/d3-format@3")
  ),
  br(),
  rHandsontableOutput("myTable"),
  br(),
  textOutput("productOutput")
)

server <- function(input, output) {
  dat <- data.frame(Values = c(0.5, 0.123456789))
  
  output$myTable <- renderRHandsontable({
    rhandsontable(dat) %>% 
      hot_col(
        1,
        renderer = "function(instance, td, row, col, prop, value, cellProperties) {
          Handsontable.renderers.NumericRenderer.apply(this, arguments);
          const p = Math.max(0, d3.precisionFixed(0.0005) - 2);
          const f = d3.format('.' + p + '%');
          td.innerHTML = f(value);
        }"
      )
  })
  
  output$productOutput <- renderText({
    dd <- hot_to_r(input$myTable)
    product <- dd$Values[1] * dd$Values[2]
    paste("Product of the two rows: ", product)
  })
}

shinyApp(ui = ui, server = server)

I don't understand the line p = Math.max(0, d3.precisionFixed(0.0005) - 2), I copied it from an example.