I think the apprentice levels help prevent some of the front loading problem pretty well so far.
If I had to change anything though I'd probably change the proficiency advancement for multiclassing. It complicates the rules and maybe messes with the simplicity they're hoping for, but since multiclassing is a little beyond the "basic" version of the game I'm not overly concerned if it requires a little more work.
For instance, going from a fighting to a caster type (or vice versa) right now doubles your amount of save proficiencies. I'd maybe say you don't pick up save proficiencies from your new class.
And I'd maybe say it takes a level of fighter to go one notch up the ladder in armor proficiencies. One level of fighter maybe gets you medium armor proficiency, but to get heavy armor you'll need to take at least two. Maybe the same thing to go from all simple weapons to becoming proficient in all martial.
If I had to change anything though I'd probably change the proficiency advancement for multiclassing. It complicates the rules and maybe messes with the simplicity they're hoping for, but since multiclassing is a little beyond the "basic" version of the game I'm not overly concerned if it requires a little more work.
For instance, going from a fighting to a caster type (or vice versa) right now doubles your amount of save proficiencies. I'd maybe say you don't pick up save proficiencies from your new class.
And I'd maybe say it takes a level of fighter to go one notch up the ladder in armor proficiencies. One level of fighter maybe gets you medium armor proficiency, but to get heavy armor you'll need to take at least two. Maybe the same thing to go from all simple weapons to becoming proficient in all martial.