Hi, yes we've managed to found the reason of these memory leaks and have already fixed it. It's most likely that we will release LTS 17.06.3 today with this fix included.
Let me explain it a bit: this bug was related to a texture cache that the engine uses for dynamically loaded scenes to speed up the loading of the same resources (this is especially noticeable, when swapping through the same several scenes multiple times). This cache suffered from memory leaks and just failed to work in some cases. Now, with the mentioned fix you should be able to load scenes in the test project you attached above without crashing.
BUT, the cache still can grow, of course not so excessively as before the fix, but it can. It perfectly suits for configurator applications with the limited amount of resources, but if you need to load/unload many big and different scenes, e.g. different locations, game levels or something similar you should consider disabling the cache at all. For this reason we've also added the configuration parameter "enable_texture_cache", which you can set to "false" and pass into the app.init() method along with others.