I don’t brew with rice, but I think you might be ok here. Red X tastes like a rich Munich Malt. I’ve used it at 100% of the grain bill and it was too intense for my liking, but cut with rice and pale malt I think it will work just fine. I’m not sure how much color you’ll get at 35% or so of the grist, but flavor wise I think you’d be in a Märzen with rice kinda ballpark.