No adjustment at the hinges, and a closer look at the existing bristle sweep it doesn't look like it's going to grow any....., definitely not adjustable.
I'm sure Lowes or HD will have something that will address the gap.
When I take the TT into the dealership this spring out of curiosity I'll see how Lippert "fills the gap".
2016 GM 2500HD 6.0L/4.10
2018 Jay Flight 24RBS
2002 GM 2500HD 6.0L/4:10 (retired)
2005 Jayco Eagle 278FBS (retired)
1999 Jayco Eagle 246FB (retired)
Reese HP Dual Cam (integrated sway control)