I'll give you my idea about your question, not sure it solves anything:
On a rig like that, expecting to shoot far, I'd go for a solid Picatinny style base tilted forward. 20Moa is enough, some use more. It gives you a solid platform from which you later will find it easy to change between scopes.
In addition to the point that you often run short of clicks on a standard scope on longer ranges, is the advantage of placing the optics in the scope nearer its best optical range. If the internal optics is near its mechanical and optical limit, it does not always perform its best.
Therefore, if you are all the way up on clicks, and the scope is out of its optical best center, you are at a disadvantage.
All scopes I have tried to put on a tilted base have had enough clicks to zero easily on 100 m/ yards. You can get a general idea how many clicks your scope has if you make a mark where it is now, and take it for a spin. Up, and all the way down. Usually a scope will be somewhere around the middle of its optical centre when at 100m/Y zero. Usually.( ordinary hunting scopes)
That's what I've been told, and as far as I know it corresponds with reality.
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