I don't pay any attention to bias. I just use the fabric in swatches. Because the pieces of fabric are small when the final block is cut out that it doesn't really matter. It has never caused a problem for me.
You can use the method for any size template so I suppose it might cause a problem in a larger block say a 4" template but I have never tried it that large. I work with 1 1/2" mostly.
The benefit of miniatures is that the problems that plaque a normal quilter doesn't exist in miniature at least for me.
I don't even know how to check for bias!! Theoretically I have heard the
explanation but I don't have to mess with it so I don't.