ip_diffim has the bool configuration option convolveTemplate implemented. With convolveTemplate=False, it switches the roles of the science and template images and performs the AL convolution of the science image to match the template. For cases when the science image is sharper than the template convolveTemplate=False and doDecorrelation=True setup should perform as well as the "baseline" case when the template is the sharper one and it is convolved.
The resulting difference image is bad quality, indicated by an order of magnitude (~ 10 times) more sources detected (half positive, half negative approximately).
This ticket covers the work by Gabor Kovacs [X] to investigate the cause of this bug.