To be fair it'd cost £2,000ish to run at Compiegne, the fences aren't that big and there's plenty of 50k+ races.
UK trainers would much rather run their horses for 5k or for 30k in Graded races, doubt half of them even look at the likes of Dieppe which is literally a ferry ride and a horse box trip of about 2 kilometres away.
Martin
British trainers would not know where Dieppe is much less look at the program book