I have toed in a lot of brake calipers with the bend technique and not once has one failed! It is easy to do but keep in mind that bending aluminum DOES stress the alloy and just might start a crack in the metal. That said, there are other ways to achieve toe-in without bending...
To get the brakes to reach on my Universal rear side pull, I filed two washers, alloy of course, to a taper and installed them under my brake pad holders. Worked fine and the same idea can be used to create toe-in without possible damage...
That said, I did get lucky and this long reach side pull is waiting, in Canada, for me to get back from my Jamaica riding...
I do prefer to bend to achieve toe-in but I have been warned to be careful when it comes to the Universal brake calipers. Other than that, not much else to add except be careful.