Change lables position/ change piece width for small piece

[zemeng2015]

Hi, emn178, I'm using your plugin and it works well. Just for small pieces like percentage smaller than 5%, the label is too close to each other

I can also hide the rendor by using:
render: args => (args.percentage > 3 ? args.percentage + '%' : ''),
but that's not requirement.
How could I change the piece size for the smaller one or label position base on percentage smaller than 3? Thanks.