On your progress, sounds like you are right on schedule using the type of bait blocks you started with. So other than reduced consumption of blocks, are you still seeing rats or finding evidence of them around? Droppings, etc? Have you found any deadO's laying around?
Since you already have it, you may want to switch one bait box to the stronger version in case some rats were not eating the first kind or not affected by it. A switcheroo to a different type bait is always a good idea once the initial consumption falls off. And going forward, leaving bait out in the boxes should be the plan for the foreseeable future. And if you are uncertain if you got em all, you could now set a few traps to use as monitoring devices.......or use a trail camera for the same purpose.