Every time blood viscosity comes up I think it's important to realize that while it is VERY important to keep an eye on your HCT, it is only one variable, in fact, the only measurable variable, that we can track to get a sense on viscosity. However, there are many other factors that we cannot account for / measure. That being said, if you search this topic with
@readalot handle you'll find a link to some very interesting data about the slope of the curve in blood viscosity that happens around (IIRC) 53-54 HCT. That is, viscosity tends to rise drastically above this level (again, all else being equal, not taking into account other factors such as genetic pliability of your vasculature, other issues that may predispose you to clotting, etc.).
So, in no way shape or form should you hand-wave high HCT. I would venture to guess that the vast majority of people who suffer heart attacks and strokes did not have HCT levels in the range that PED users walk around at. But because we can measure it, we should use that data as intelligently as possible, though splitting hairs about 48 vs 51 vs 52 I don't think is helpful. Meds like tadalafil are critical for PED users not just for BP (minimal impact) but moreso for the positive impact they have on the endothelial lining. Also, nattokinase is a winner in this area. I also like fish oil / Vascepa for the anti-inflammatory and modest blood thinning impacts.
Control your lipids and BP as aggressively as you can. Find meds / supplements that minimize oxidative stress, and manage your HCT. None of this guarantees anything but it's your best chance at harm reduction based upon what we currently know.