I just used that very coat to do the floor in my Ring, its very rough, dont want to put a knee on it! i used a 1 litre tin to do the areas in the picture and used foam rollers from tool station- 49410 item code.
But i feel a very faint tach still so i think you need to be very sure you have mixed the harder in well enough, so mix three times what you think is mixed to be safe, or use a drill etc to make it a proper mix!