This is what I believe is the case, but don't take it for gospel as I was not hands-on with this install.
The stock BPF cartridge has a limitation on the extension. It's not a hard stop on the fork tube. The Öhlins kit that we have to use (which is adapted from another bike) has a longer stock stroke, which Seacoast had to shorten to make work (but still extends the stroke vs the stock EBR BPF fork).