From my understanding the purpose of the lock stitch is to simply hold the splice in place when it's unweighted. When a load is on it it clamps down, but can work loose if it is loose. So i always figured if i simply did a nice seizing like you did there (which i imagine you stitched thru the rope several times) that did the same purpose and then some. I even went so far as to splice a larger eye, then do a seizing to size the eye around a biner. This way the clipping wears on the marline and not the rope.