Dave's opinions:

Corsair no, not safe to keep running near max.

Other better brands yes they are. Where you have them is on the border of what I would do with the ones I use, perhaps a bit over.
I have had EVGA 1300 units running @ close to 92% rated for years now with no issues.
Same with some of the earlier Seasonic

Corsair I will not run above 75%. Just have not had good luck with them in PCs or in mining.

-Dave