Many patterns have you knit the ribbing on a smaller needle and change to a larger one for the main part of the pattern. Usually this is done immediately after finishing the ribbing. But shouldn’t we change to the larger needle before the very last row of ribbing? Because if the last row/round of ribbing is knit with the smaller needle, those live stitches that will be worked into on the following row will also be smaller. Therefore knitting them with a larger needle should make no difference on the very first row. Am I thinking about this too much? Probably. But please let me know what you think.
Try both and see what you like better! There are some things I do in an “unorthodox” way when it comes to knitting because I like the result better so. Knitting is fun because it allows us to freely experiment and find our own preferred solutions.
While I understand what you mean, personally this is not a place where I would do differently from what the pattern calls for. If I change the needle size at all, I would do it after the ribbing and not when one row of ribbing is remaining. Personally I think it looks better this way.
I agree generally with what engblom said.
I also think it may not actually make as much difference as you might be thinking. When you change needle sizes (or incr/decrease), the knitted fabric doesn’t abruptly change to the new gauge, but has to transition gradually over a few rows/rounds, because the larger and smaller stitches (or shorter rows/rounds) are still connected to each other. (And of course the finer the gauge overall, the less difference the exact placement of the change should make…)