I’ve noted this is, for me, directly related to add-ons.
I’ve been commenting in the loading times thread and during testing for this bug on my laptop (significantly less powerful than my desktop), I’m seeing a 9 minute 29 second load into cockpit time for the 787!
However, once I stripped the sim of all my add-ons save for the Deluxe, Premium, WUs, CUs, Top Gun, and Bullseye Landing content, the load into the 787 dropped to 02:34.
Something whacky is going on with load times related to add-ons, I think. Unless one of the add-ons itself is hanging the load.