Dramatic performance improment. Great job, yn0t_.
And I'm finally able to access the ID3v2 comment field.
Well, actually I can't get emphatic to give me the custom info mode option when trying with a simple example. Anything wrong with my syntax?

[emphatic]
custominfo1=vscroll "comment" medium 0 0 128 32 10 0 -1

However, the flexible way you implemented this feature looks promising.