I used to treat them as two different powders, in that, I would perform at least a minimal, yet separate work up, thus wasting components that I could other wise be using as intended. But I got to thinking about it and realized, that probably the most effective and efficient manner of dealing with two different lots, was to blend them together right from the get go. By doing so I get one powder with load to load consistency, which only requires a single development.
On my shelf right now are different lots that I mixed- 5 lbs. of IMR-7828, 2 lbs. of SSC mixed together, 4 lbs. of H4831, and 3 lbs. of the SC also mixed separately, 2 lb.s of RL22, 2 lbs. of IMR-4350, 3 lbs. of Varget, 1 lb each of H110 and 296 mixed, 2 lbs. of Longshot, and 6 lbs. of HS6. But as you can see, I don't mix SSC or SC with a standard cut version, they tend to separate just pouring them out of the canister.
GS