Glue-up strategy for mitering 5/4x6 Ipe border frames

I am currently tackling a 600sqft deck using 5/4x6 Ipe and the client is demanding mitered corners throughout the entire perimeter frame. In this coastal humidity, I am worried about the miters opening up after a single season. I have been using West System epoxy for the joints, but the cure time is killing my production speed on these long runs. Are you guys having better luck with a specific structural adhesive that handles the expansion/contraction cycle better, or are you just sticking to biscuit joints and heavy-duty stainless screws? I have experimented with Domino joinery on some smaller accent benches, but it feels like overkill for a 45-degree rim joist connection. Any feedback on your go-to method for keeping these corners tight for more than one summer would be appreciated. The client is paying a premium, so I really need this to hold up.