Hey there. Thanks for checking out this project.
I just downloaded the project from the asset lib in one other existing project of mine in 4.4.1 and had no issues.
The export_custom is there only to store the values you set up on the property list, in latest versions it would be the same as export_storage. The property list is populated on _get_property_list().
You can see here that it gets the list of animations to populate the editor with and it shows them one by one. That's so the editor shows you all required buttons or animations but they are stored in a packed manner instead of a thousand variables.
In your screenshots you can see the Input and Animation group of parameters, those are where you set up.
Viewing post in Expandable Platformer Controller 2D - Godot comments
Hi, thank you for replying to me.
I currently still couldn't quite use it as intended, as there are strange bugs. But I'll keep investigate.
In my current project right now, I decided to implement my own custom player controller. Your tool (and the original one from Noasey) gave me some good ideas on how I can implement my own, so even if I don't end up using your tool, it was valuable, so I appreciate your work.
Thank you for your kind words. Partly thanks to your encouragement, I have also shared one of my tools I'm using to develop my project on my page. It's a tool to create pathfinding behaviors in a 2D platformer (that I also extend from the work of another creator, TheSolarString on YouTube). I hope that it can also help other people in developing their own games.
Godot Asset Lib asset is approval pending.