Hi. I'd like MoSync provided an easy way to customize applications for different devices.
I don't know how hard it would be to implement this but J2MEPolish has a very nice way to allow customization:
"To enable customized versions of your application you can set up one base and several customization root directories with J2ME Polish:
* In the base root you place all common resources, design settings and texts.
* In each customization root you can include specific resources, design settings and texts that take precedence over the common ones.".
Here they explained in details what they do.
http://www.j2mepolish.org/cms/leftsection/documentation/customization.html
Regards.