This is the reason I proposed a crop feature.
As we all know, not all images are the same size and as of now, I believe your software will save the images in the same size as the originals but instead of saving them as a size equal to all others, they may be different sizes and sometimes that does not look good. That I why I proposed a crop feature. The crop feature I proposed probably isn't like the others you see in other software. The crop feature I was talking about will determine the size of the smallest picture in the collage and set the crop box to that specific size. However, the crop box should be able to be moved on each image for the best end product.
I hope I have not confused you even more.