To add on to this: this only matters if you have a very slow computer and want to generate a very large batch of scrambles at once.Random move scrambles are quicker to generate.
(Random-move 444 scrambles have noticeable biases, especially in how the centre pieces are distributed, as only about 1/3 of the moves even break up the centres at all. It's not entirely uncommon for a scramble to just have F2C be almost solved. Never use random-move scrambles if you can help it; if you really have to, set the scramble length to at least 50 moves.)
