You can check changes of your models without restarting the WE.
You see, when WE needs to display a model, it loads it in the RAM and makes an association path<->model. So if you re-import the model, it won't re-load it in the RAM but keep the old version.
However, you can re-import your model, give it a different path that has never been loaded and immediatly save the map. You may add a figure at the end of the re-imported model's path, for instance.
It's quiet tedious (if you forget to save the map just after re-importing, you have to do it all again from beginning), but it's less tedious than closing and re-opening WE everytime.
Hope this helps.