I reached out to our coping manufacturer and below is what they had to say...
I have attached a picture of our CPBL120 and our LTF20.
The larger channel looks like the width of our LTF Liner Track Bead Filler. We usually sell this in 20’ lengths but we can roll it out in longer lengths if needed.
If you decide to do this our part number for 20 feet is: LTF20
It must be indicated on the order is they want a continuous run and not cut at 20’. It would probably be best if the order were sent to my attention just to minimize any errors.
Hope this helps.