I just thought of something: Since the JUCE components are lightweight, is there really anything that would disallow subpixel positioning? I.e. imagine to be able to set the bounds of any component as:
comp->setBounds(23.45, 10.27842, 100.7, 50.23);
I guess there will be issues with this, but it would be cool, wouldn’t it? 
I’ve wondered why juce doesn’t allow float positioning of components ever since I started using it. I think the main reason it’s not supported as of now is that changing the functionality of something so fundamental as a component’s position would require a major overhaul of the entire application section of the codebase.