Leaflet and Flyer PosterProxy

Question

I added a leaflet TextPath plugin to a brilliant application similar to this example . This works very well:

output$fullscreen_map <- renderLeaflet({
  points <- points_reactive()

  points %>%
    leaflet() %>% 
    addTiles() %>%
    fitBounds(~min(lon), ~min(lat), ~max(lon), ~max(lat)) %>%
    registerPlugin(textPathPlugin) %>%
    onRender("function(el, x, data) {
                data = HTMLWidgets.dataframeToD3(data);
                data = data.map(function(val) { return [val.lat, val.lon]; });
                var layer = L.polyline(data);
                layer.on('mouseover', function () {
                this.setText('  ►  ', {repeat: true, attributes: {fill: 'blue'}});
                });
                layer.on('mouseout', function () {
                this.setText(null);
                });
                layer.addTo(this);
    }", data = points)

})

According to the docs, now I would like to use leafletProxy()so that the whole map is not redrawn whenever the reactive data source changes. Alas, using the following code snippet

leafletProxy("fullscreen_map", data = points) %>%
  onRender("function(el, x, data) {
              data = HTMLWidgets.dataframeToD3(data);
              data = data.map(function(val) { return [val.lat, val.lon]; });
              var layer = L.polyline(data);
              layer.on('mouseover', function () {
              this.setText('  ►  ', {repeat: true, attributes: {fill: 'blue'}});
              });
              layer.on('mouseout', function () {
              this.setText(null);
              });
              layer.addTo(this);
  }", data = points)

It does not work properly. I assume that this is due to the fact that it onRenderis called only when a new rendering appears, and the whole point leafletProxyshould not be displayed again? If this is correct, is there a way to do this using other methods?