Yah, in my revamped weekly exercise routine, I've taken a bit from here and there (including that 20 plank exercise video you posted a while back) and tried to fit it in to the logic of the day's exercises and their place in the week's progression. There's a million different things we could do, so the trick was to experiment and find what works for me, given my fitness goals and time/energy constraints. I daydreamed a lot over this last summer about different stuff, but I came back to weights one day, running the next, just as I had always done, but with refinements to my approach in each. I'll continue tweaking, but I'm really enjoying the newly honed regimen so far, even though it hasn't been fully realized yet, due to October's setback.
P.S., some of those Myrtl exercises are even better with ankle weights.