We encountered the same problem with the Deuce Roadster we were building for a pals wife,... Bill had bought some of the first fenders offered by Brookville,... (Made by Funk).
The new ones are great!
He didn't want me to cut the back of the fender,.... So I asked him,
"Bill,.. can you make us some Coffee ?"
,..... Sure ! he said as he tottled off to the house,..... when he came back,.... I had one cut

, and said,... well, we might as well make them match !
I made the cut about a half inch from the flange, The other problem we had, was that they were made with deep draw steel and were still pretty soft,... Bill leaned on one and put a dent in it,....
There was a issue with the very first rear fenders as well,... when they crimped the wire in the bead,.. it was to tight and kept the fender from pulling up tight to the body,... the had no twist,.... But !,.. To Brookville's credit, they called Bill before we even mounted them, told him of the problem and said they would exchange them.
In my personal experience, Brookville has been a first rate company to deal with,.... with really great products.