Observe click event on a synced map in Leaflet/RShiny - r

Question

I'm creating a mapping visualization in RShiny, and I'm trying to detect a map shape click. I know that you can do this by using observeEvent, but my issue is that I'm using leafsync to synchronize my maps, so I have to wrap my Leaflet maps in a renderUI. Here's a simplified version of my code:
ui <- fluidPage(
navbarPage('CS4All and CTE Progress Visualization',
tabPanel('Map',
div(class='outer',
sidebarLayout(
mainPanel(
uiOutput('synced_maps')
)
)
)
)
)
)
server <- function(input, output) {
output$synced_maps <- renderUI({
# --- CS4ALL MAP
cs4all_map <- leaflet() %>%
setView(lat=40.730610, lng=-73.935242, zoom = 10) %>%
addProviderTiles(providers$CartoDB.Positron) %>%
addPolygons(data = ctecscrs_geo,
stroke = TRUE,
color = '#808080',
weight = 1)
# --- CTE MAP
cte_map <- leaflet() %>%
setView(lat=40.730610, lng=-73.935242, zoom = 10) %>%
addProviderTiles(providers$CartoDB.Positron) %>%
addPolygons(data = ctecscrs_geo,
stroke = TRUE,
color = '#808080',
weight = 1)
# --- DEMOGRAPHICS MAP
dem_map <- leaflet() %>%
setView(lat=40.730610, lng=-73.935242, zoom = 10) %>%
addProviderTiles(providers$CartoDB.Positron) %>%
addPolygons(data = csd_dem_geo,
stroke = TRUE,
color = '#808080',
weight = 1)
sync(cs4all_map, cte_map, dem_map)
})
}
I tried adding the following both inside and outside of the renderUI function:
observeEvent(input$cte_map_shape_click, {
click <- input$cte_map_shape_click
print(click$id)
})
and in both instances, nothing printed to the console. Does anyone know if it is possible to observe events on synchronized maps in Leaflet/RShiny?