Just throwing this out there....., the photos suggest that this might be one of those cases where a Round Spring Bar style WDH isn't ideal for the lower frame profile of the Hummingbird TT.
Just curious...., I wonder what style WDH's other 17RK Hummingbird owners use and amount of ground clearance they experience below the spring bars.
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 (Strait-Line)