I bought one of these several years ago and have used the daylights out of it with no bucket damage or warpage. This past summer I also added "The Thumb' grapple to the top of the bucket. This combination of the debris fork and 'The Thumb' makes brush/ debris clean-up phenomenal. Just open the thumb, drive into the pile, clamp the thumb down and drive away with a huge amount of debris that doesn't move until you are ready to dump it. The multiple bars/ tines keep a lot of stuff from falling through vs just 2 forks.
Prior to this, I made my own clamp-on forks from 2 X 3 square tube with 2 sets of clamp bolts on each fork. THey still shifted, so I picked s good with and made an "H" bar out of angle iron to bolt between the forks once installed on the bucket. This eliminated the shifting problem. These also did not bend or warp the bucket. One thing I should mention is that prior to doing this type of work with my pin on loader bucket, I purchased some either 3/8" or 1/2" X10" flat bar and beefed up the bottom side of the bucket so the entire bottom of the bucket is equal thickness with the back edge of the scraper blade. This was done purposely so my bucket wouldn't have the built-in 'smile' I have seen in so many other buckets. The top of my bucket also has an added 2" square tube brace welded across it for top side reinforcement.