A given rose cane has a limited life span which depends on the variety. I see there has been a fair amount of pruning on that cane. Is that from training, or from death? If the laterals have started dying off, the cane is reaching the end of its life, and pruning it out is a reasonable proactive decision.

I do seem to kill canes by bending them around the guard. They seem flexible when I do it but then they often die off.

Most 'hardy' climbers come from genetics that do not tend towards flexibility. Sometimes, you can do things with the laterals, but the usual training is to let them grow up, then cascade down in an umbrella shape. Ramblers can be more flexible, but even there the hardy genes cause problems.

Years ago, I grew Alexandre Girault. It rarely bloomed, since it rarely overwintered much of anything, but it was extremely, amazingly flexible. I think I could have tied knots in it. The entire texture of the canes was different from anything else I've dealt with, and I did often wrap it around its pillar.