Yes I would use EQ for reverb. I have the Valhalla stuff as well. I would recommend rolling off at least 200hz with a low pass filter. That way it will take away a lot of the muddiness away from the reverb, as reverbs tend to be quite muddy at the lower end and should keep the piano still sounding crisp and clear. The rest is dependable on how you want to approach the EQ creatively.