I have sent a manuscript to Optica, I have published there before and in other high-impact journals. This time my submission was first sent to 5 referees (I listed three names as requested). I thought that is reasonable since some will not be available etc. One ref agreed and the other said they were unavailable. Then the editor sent it again to 6 more referees. Now, 2 months later, I'm expecting to have 6 referee reports (5/6 agreed). This is still round 1.
I have never had this number of reports, including Nature or Science. It was usually 2-4 referees. Besides the inefficiency and time consuming process for all involved, what's the point? Is there a cap limit on this? Should there be? Has anyone had a similar experience?