PCB Layout - Best way to hand solder under pads
Seems this device is designed to be cable-mounted. I very doubt people will be able to mount it onto the board through vias. There're several risks to it:


insufficient solder: bad connection through vias, which may break in most critical situation. I think you do not want returns and bad reputation for bad kit design;
too much solder: risking to short the pins, potentially frying the device.


If you'd be soldering it yourself, probably you can manage to have acceptable soldering quality (after several broken boards), but as others will be soldering it I very doubt they will gain required skill to solder them properly.

Go for separate components, even if it is more cost and more work on soldering.