There are certain "handshakes" that have to be carried out when flashing anything through the OBDII port to the ECU. Some of these handshakes are not required when flashing directly to the ECU (as in a bench tune, or opening up the ECU and connecting directly).
These procedures for OBDII must be identified, and implemented into an ECU flash. Some cars are easier to nail down than others. Some are simply using another vehicles read/write system, so it already exists. Some are using something different, and have to be sorted out. There are a lot of technical variables at play.
At this time, no one is offering an OBDII ECU flash available to purchase. That does not mean that it will not be figured out. It just means that at this time there is nothing that works consistently. There are a few software/hardware companies at the top of all this, and once it is sorted out it will trickle down to others. Dimsport is one of those companies, and we are working with them to find what works. There is no given ETA with these kinds of things, and I can tell you that they, as well as us, typically will keep it pretty close to the chest until it is 100% finished and ready.