Using throttle/debounce with numericInputs and renderUI/uiOutput

app.R

library(shiny)

ui <- fluidPage(
   fluidRow(
     numericInput(
       "obs_low",
       "Minimum obs",
       value = 1000,
       min = 500,
       max = 5000,
       step = 100
     ),
     numericInput(
       "obs_max",
       "Maximum obs",
       value = 4000,
       min = 500,
       max = 10000,
       step = 100
     ),
     uiOutput("likely_ui")
   )
)

server <- function(input, output, session) {
  output$likely_ui <- renderUI({
    
    # obtain the min and max obs
    min_obs <- input$obs_low
    max_obs <- input$obs_max
    
    median_obs <- reactive({
      median(c(input$obs_low, input$obs_max))
    })
    
    min_obs_d <- reactive({ input$obs_low }) %>% debounce(1000)
    max_obs_d <- reactive({ input$obs_max }) %>% debounce(1000)
    median_obs_d <- debounce(median_obs, 1000)
    
    validate(
      need(min_obs < max_obs, "Minimum obs must be less than maximum obs!")
    )
    tagList(
      sliderInput(
        "prev_likely",
        "Most Likely obs",
        min = min_obs_d(),
        max = max_obs_d(),
        value = median_obs_d(),
        sep = ","
      )
    )
  })
}

shinyApp(ui = ui, server = server)