Calculating Spoke Length

Question for the more knowledgeable builders out there. DT Swiss calculator is coming back with actual spoke measurements of 294.2, 295.5 and 295.4. Depending on the nipple length I pick I get a different suggested spoke length. Seems a bit odd to me as I would have thought I want the spoke to be the same length regardless of nipple - I want the spoke to end in the same position relative to the rim. Longer nipple just means more thread engaged and protrudes further from the rim?

I was planning to go with 294 on the 294.2 and 295's for the rest. However calculator is recommending 293 (294.2) 295 (295.5) and 294 (295.4), leaving up to 1.4mm off seems excessive to me when I could be within 1mm