It depends what you mean by proxy. In the plugin, you have the
Use Instances option in
Scene Manager > Output, which ensures that the plugin will export using Maxwell instances whenever possible. You also have the
Proxies option (also in
Scene Manager > Output), which is described
here. The
Proxies option works manually, or with a Ruby script named
proxy.rb (discussed
here), which replaces components in your SketchUp model with simple bounding boxes.
In Maxwell Studio, you have
MXS References, which are not yet supported in the plugin.