The bullet in question is described by the maker as being “designed for the long-range shooter”. That’s code for being of “soft” construction. Seafire’s experience makes good sense as he describes just such a bullet. Top velocity loads would be a poor choice for closer range shooting, as the OP understands. Using a faster propellant like IMR 4198 is a better idea IME than a slower powder, since the latter may not burn as well in reduced loads. Why not just drop the OP’s current load a grain or so first instead of starting over with a new powder? BTW, I’ve used BlueDot with lighter bullets in my .243 to good effect, although I don’t think I ever chrongraphed the loads.
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