2024.9 test result :
nearly half million polygon, using arcgis javascript api lastest version v4.30.
when hover the polgyon, responsing speed is extremely fast, nearly real time, not noticable delay or laggy.
The only concern so far is all polygon has been simplified as triangle, this bug need to fix.
https://transparentgov.net/json2tree/datahub.io/embed/featurelayer.html?backgroundlayerurl=https%3A%2F%2Fservices.arcgis.com%2Fv01gqwM5QqNysAAi%2Farcgis%2Frest%2Fservices%2FPADUS_Management_Areas%2FFeatureServer%2F0&layer=Management+Areas
More to test, search for keyword 'pad'
https://transparentgov.net/json2tree/esri/server/folder.html?org=https%3A%2F%2Fservices.arcgis.com%2Fv01gqwM5QqNysAAi%2Farcgis%2Frest%2Fservices&url=https%3A%2F%2Fservices.arcgis.com%2Fv01gqwM5QqNysAAi%2Farcgis%2Frest%2Fservices&select_folder=756&select_layer=0&arcgis_online_token=&timeout=10000