What type of field are you using? Is the plugin stripping the shortcodes? I think all you'd need to do would be either:
echo apply_filters( 'the_content', slt_cf_field_value( 'my_field' ) );
Or just:
echo do_shortcode( slt_cf_field_value( 'my_field' ) );
The former, I think, will parse the shortcodes as well as apply all other content filters. The latter would just parse shortcodes. Depends what you need.
I could possibly include parameters for slt_cf_field_value to apply content filters to what's returned, but I generally try to leave things flexible for developers, so it's a low priority.