Oh drat, I see that others have also discovered that this needs patching for 1.0. It's been a long time since I used C# regularly enough to know offhand but the error message sounds like a tweak and recompile would fix it.

Not working anymore :(

=== It's Your Choice 1.0.0 Errors ===
<...>\steamapps\workshop\content\333640\3099213021\Leveling.cs(150,14): error CS1503: Argument 2: cannot convert from 'System.Collections.Generic.IList<string>' to 'System.Collections.Generic.IReadOnlyList<string>'
== Warnings ==
<...>\steamapps\workshop\content\333640\3099213021\Injector.cs(30,19): warning CS0618: 'Popup.ShowOptionList(string, IReadOnlyList<string>, IReadOnlyList<char>, int, string, int, bool, bool, int, string, Action<int>, GameObject, IReadOnlyList<IRenderable>, IRenderable, IReadOnlyList<QudMenuItem>, bool, bool, int, bool)' is obsolete: 'Use PickOption'

broken RN gives this error
=== It's Your Choice 1.0.0 Errors ===
<...>\steamapps\workshop\content\333640\3099213021\Leveling.cs(150,14): error CS1503: Argument 2: cannot convert from 'System.Collections.Generic.IList<string>' to 'System.Collections.Generic.IReadOnlyList<string>'
== Warnings ==
<...>\steamapps\workshop\content\333640\3099213021\Injector.cs(30,19): warning CS0618: 'Popup.ShowOptionList(string, IReadOnlyList<string>, IReadOnlyList<char>, int, string, int, bool, bool, int, string, Action<int>, GameObject, IReadOnlyList<IRenderable>, IRenderable, IReadOnlyList<QudMenuItem>, bool, bool, int, bool)' is obsolete: 'Use PickOption'

Please update

The only required change was Line 150 of Leveling.cs
Options: attachables.Names,
to
Options: attachables.Names.ToArray(),

I posted a fix on the workshop, I removed the compilation error but there may be unforeseen errors lurking. Feel free to use it to update the original and thanks for creating such a fun mod!

I think this finally broke. Damn shame. Keeps failing every time I launch the game. Has been at 1.0 since 2023. Seems like it wont be updated. Bummer, I hope they fix it. I was tired of random feet growing out of my ass.