Picking up stitches on the diagonal edge

I’m knitting a baby blanket on the diagonal, using a chunky yarn (12 ply Australian).

I’d like to add a lace border, very simple. The pattern calls for knitting it separately, and then sewing it on which I’m not keen on. I checked it out on Ravelry, and some users suggested picking up the edge stitches and knitting it in.

I watched the video on this site about how to pick up stitches, and it makes a lot of sense. However, it says to not pick up only one strand along the edge. I’d have to go a lot deeper into the work to pick up 2 strands, and I think it would ruin the simple inc/dec border the blanket has at the moment.

Seeing as I’m using a chunky yarn, does it really matter if I use one strand, or should I strive for the two?

Try it out both ways. Each edge stitch has 2 legs of the stitch. To pick up 2 strands would be picking up both legs. Picking up a single one may stretch out and leave gaps, but since it’s on the diagonal, that might not be a problem.