Yes. You are then only guaranteed the calendar days off that your vacation, buffer, and vacation extension (can’t remember if the correct word with reserve vacation is extension or expansion?) occupy. The rest of the days are “requests”. CRS will not leave a single reserve day sitting by itself either.

From memory here, so someone may correct me if the 2015 CBA changed it, but they have to leave the leftover R days in place and add any back in that are needed either in a new block or attached to a leftover. In other words, if you had a week of reserve in week 1, then had the rest of Reserve in weeks 3 and 4 which your vacation killed all but 2 days that were removed due to buffer, they couldn’t reconstruct all days in week 2. They would have to leave week 1 alone, and add the two days reconstruction on either side of week 1, or the two days in week 3.

Sorry if that’s clear as mud. I know what I mean, but it’s hard to express the contorted process elegantly.