I use the web-based trip planner (https://www.tesla.com/trips) regularly and find the interface somewhat clunky. Not sure if Tesla reads this but I don't think it would take much to make improvements.
1. When I use Google Maps on a desktop computer with a mouse, I normally zoom in and out with the scroll wheel. You can't do this on this web page. When you try, the screen goes grey and a message tells you to use the + and - links on the map. This is an easy fix at least on Google maps. It's a matter of settings. They can keep the + and - on the map for those who don't need it.
2. There needs to be a way you can set a personalized default for it to remember your Tesla model. It's a pain to go in each time and make the selection (Mine is a Model 3 LR).
3. In planning a long trip it chooses the best route and indicates the superchargers on the route, etc. That's great but I wish the list of the superchargers that are recommended along the way on the left panel of the screen were in a much smaller font so that more would show up in the panel without scrolling.
4. Google Maps allows you to drag a point along the way to another location so that you can manually re-route the trip. You can't do that on the Tesla map. The trip I am planning to MN takes me about 35 miles out of the way near the beginning of my trip.