Admittedly last season we had issues working deals for Pulisic, Broja, Gallagher, Ziyech, all players chelsea deemed surplus to requirements yet all talks got nowhere. Arsenal are far more open to negotiations and more genuine in negotiations. In the Abramovich era we had pretty good relations with chelsea, under Boehly, I think the bridges are burned.
Chelsea will probably listen on Cucurella, but we should stay well away from helping them with that player who is falling into the bracket of "one season wonder".
Per reports, discussions are advancing with Arsenal on Tierney.