I think, for me at least, I am trying to learn how not to do that from the beginning.
However, the process involves mistakes, missteps, trial/error etc. Unfortunately, the journey of refining technique implies that you are starting off with something rough, and trying to temper it out into something refined.
Something rough in my experience sometimes involves taking a hard nikkyo. It isn't ideal to give or take a hard nikkyo, but it happens every now and then as you work to refine the technique.
Babies fall down as they learn to walk.(heck grown men trip every now and then.)
Again, my opinion, its the birthing pangs of refinement in this instance.
For sure, Maggie, you're right - I guess what I was really thinking about is, I haven't seen much actual, real teaching out there about "painless Nikkyo" - mostly I see just hard joint locks that are either designed to be painful, or have to be because there's nothing else to them that would make them otherwise....