So I recently picked up another DI-4 and yes it's a love/hate relationship but with all these configured sumps that have sock holes built in, well it's just easier.
Anywho I noticed that they did some small changes to the top part of the hinged frame. This is comparison to my older '18 and '19 models. They now have notches on both sides of the unit so that you can place the water level sensor on either side which is good. They also seemed to have addressed ONE of the reasons why fleece can snag and tear. There are 2 guide rollers on the side where you start threading the fleece. The lower guide use to be very close to the frame bracket and this might have cause tearing for some like myself where stomatella get wedged or when you start getting a very rough bracket surface from all the calcification. So they raised that roller guide a bit which makes sense but while trying to address one problem, they have created another which is that the fleece no longer stays taunt because it's not doing a 90º turn before lining the filtering area of the bracket. Now when the void space in the chamber starts to fill from clogging fleece, it just starts multiple seepage points along the edges because there is no longer any tension on the clean roll side.
Great job Coralvue.