Concerning the picture of what looks like fiberglass debris on the screen. Could it have been generated when the fiberglass tank was cut open?
I have made my own version of the CAT tank for about 20 years. I use an automotive fuel filter, some parts I machine, and a Sullivan tank. When I started this I thought about how often I might want to change the filter. This is an automotive fuel filter, and most of us don’t change them in our cars more often than 50,000 miles, if even then. So if you get 30 MPG you would be changing it after about every 1,700 gallons of fuel. So since I filter the fuel into my jets better than I filter the fuel into my car I decided that I would probably never have to change the filter in the jet. So CATs decision to seal the system makes a lot of sense. It also makes me think that if someone is having an issue it probably is not due to a lack of pre-filtering.
One thing I have seen over the years is the growth of something in my fuel system that I strongly suspect would have plugged the filter. I saw the black clumps of stuff in a fuel line while getting the model ready to go flying. I took the fuel system apart, cleaned it and replaced the filter and all was well. I would tend to think this is more likely the culprit behind the issues being reported. It probably would not have matter what filter system was being used, it would have been plugged up, and changing the filter would have fixed it – for now.