Their stacking kits are elegant solutions however it does restrict us to using the silicone bands in the pre-fixed location(s) they choose.
I've got no background in hardware design or anything so excuse my ignorance but given how close all the hardware buttons on the T3 are clustered together in the upper 2/3 of this small device, it does limit them on where they can even put their attachment hooks in a manner where the thin silicone bands don't overlap their own hardware buttons as it does become an issue when you try to access them.
This is less of an issue when the stacked hardware has the same width but the problem becomes exacerbated when you have a DAC/AMP that is wider than the T3 as the band is stretched away from the device making the buttons harder to access if it does cover it up, especially when you're trying to manage it in your pocket.
I'm not against them offering a stacking kit, but by changing the position of the hardware buttons, in addition to offering a stacking kit, they are providing us more options in how we choose to stack our devices, which is particularly handy given the various positions of buttons/knobs on portable DAC/AMP's that others possess.
I'm not claiming their stacking kit or the proposed changes will suit everyone's DAC/AMP button layout combo, but it does allow more possibilities than offering their kit alone. In it's current iteration, for those who end up using their own silicone bands, they are limited to only the bottom 1/3 of the T3, otherwise they will compromise on either covering their buttons or covering the touchscreen.
Of course if a change like this is very costly or will take too much development time then scrap the idea as we all want the device sooner rather later