If before assembly you drill matching belt retainer holes in the idler rib — by stacking the driver rib on top and drilling straight through, then in the future when you want to change or tighten your belt, or switch platforms, you can run an allen or ball hex wrench through the ider to the bolt heads on the driver to do so, without completely disassembling the platform.
This trick will also work with the acrylic platform. With the ABP it should also work if you drill much larger holes in the outside end-pieces, as otherwise aligning two small holes and the bolt will be very difficult.