When I first started reloading I kept seeing/hearing people talk about their rifles liking near max "hot" load. But in my experience (only 3 yrs reloading) my r700 prefers low to middle load for best groupings. For example for Varget in 167gr the starting load is like 32 and max in 44. Best 3 shot grouping came at 33.5. I was able to get 5 shots at .264" using 33.5. I purchased the 5lb D4895 (closest to Varget) and cant wait to get to the range for load development.
What you're describing isn't unusual.
Things change as components/rifles change.
I have some very accurate rifles. If I stick to one bullet/powder/primer, there is usually a specific sweet spot, where the harmonics are very consistent. Sometimes it's at the high or even slightly over what manuals suggest.
Most rifles like the loads to be somewhere between the minimum and maximum range.
A very astute friend recently purchased a lovely new Kimber, chambered in 308Win. It shot several brands/shapes of 165r bullets into sub moa groups.
The issue he had (sold it) with it was that it would only do this about 1 grain off suggested minimum charges, with all powder types tried, at least 6.
When the powder charge increased, the groups opened up dramatically
For his purposes, he needs better velocities, with that particular weight bullet. It's what he hunts with from 20m to 500m and he knows the trajectories/drift mannerisms inside out.
IMHO, you're going to be very pleased with D895.