We used to stock the VMP-PRM2, but now it is a special order item. The PRM2 will work fine with a 90cm.
I guess putting blocks on top of roof would be more risky than drilling thru the roof
what if is too windy and the concrete blocks fall off
I almost took a picture of one of these yesterday for this thread. There is a smoke shop in a neighboring town that has a Hughes data dish on the peak of the roof with what appears to be a Baird universal peak mount. There are 4 solid low profile concrete blocks on each side of the peak holding it in place. Its been there for a few years through intense thunderstorms with no issues that I am aware of.