Every time a room is saved, the previously saved version is added to the recycle bin on windows. Both the png and txt are recycled. The end result of this is that frequent use of Rained can result in thousands of files pooling in the recycle bin at an alarming rate. This issue is present in both v2.4.0 and the latest nightly build (2 weeks ago from the creation of this post).
The top of the recycle bin after light use of Rained.