Better Class/Race Advancement Integration

[aprusik]

Is your feature request related to a problem? Please describe.
Weapon/Armor Proficiencies are not included in imported class advancement. Ability score improvements also give a feature instead of just using the built-in ability score improvement advancement. Currently it is very difficult to use purely imported classes as a reference for leveling up, as the advancements will miss things or import features that don't do anything because they require a choice (such as ability score advancement). With the additional lack of importing the class table, (which I think should be included, but that's another matter) this makes it necessary to reference other material to level up a character.

Describe the solution you'd like
Imported class advancement should match the SRD class advancement model.

Describe alternatives you've considered
The current method at least does something for everything needed in class advancement aside from weapon/armor proficiency. Not sure if there are any alternatives that make sense.

Additional context
The included SRD class advancement includes the following advancement types that are not included in imported classes:

• weapon proficiencies
• "original class only" tags for non-multiclass features
• choice advancements for things like warlock invocations
• the "Ability Score Improvement" advancement

All these allow for smoother integration into the 5e system and provide an easy reference model for other modules that expect things to be in certain places.

You could potentially go farther than the SRD's limited subclass options and provide a "choice" advancement for players to pick their subclass from those available from import.

Here is an example of the difference between the imported warlock advancements on the left, and the SRD on the right: