It is not essential that you use a locked brummel if you take other measures to prevent movement of the splice. Those include the bury followed by stitches and or whipping.
There's also the Shoemaker's splice
where weaving four or five times substitutes for the locked Brummel.
That said, after you've done a few, it shouldn't be hard to imagine a sweatshop in which the locked brummels with access to both ends of a 13 foot length of 2.5mm Amsteel are done at the rate of 100 per hour per worker. That is BEFORE passing the cordage on to the next workers, where completing the bury and tapering it do take somewhat more time.
So much more time that you'll be tempted to shortchange the taper. Resist the temptation. A well done taper may be as effective for strength as having spent twice as much on heavier cord.