If you look at what most people target for their PO4 numbers, .46 is very high. There are plenty of successful reef tanks, even SPS dominate tanks, that run their phosphate that high or even higher. One thing you may notice is that SPS corals may tend to brown out and not have vibrant colors at that level, but there are many other factors that contribute to SPS coloration. If you are running LPS or softies then I don't think you will have any issues with that PO4 level.
What is more important would be how well your feeding habits and export methods are doing at maintaining that level and not allowing it to continue to slowly creep up over time. What are you using to control your nitrate/phosphate??