I don't think he did anything special with the plates in this part. If I recall correctly, (at work can't really look up the part) his armor was just cracked all over from the pressure of the claw which made the stormlight "glow" around him as it was escaping the armor. Could be wrong but thats how I remember it
Also I am more incline to think the plate is not from the nahl bonded spren. As state before, Syl turned into a shield with Kaladin and didn't crack at all. Where a couple good hits with a shardblade and shardplate cracks and breaks, so if Syl makes Kaladin a full suit of armor, wouldn't it not crack like shardplate does?
Maybe one of the KR orders main thing is to make shardplate since they weren't all fighters and some where other things like diplomats? Nothing to really support this, just an idea.