to the OP and other ultralite HTT/TT owner:
if you have a trailer that's frame warranty has expired, go for it. get a receiver welded and braced to the frame and bumper.
if it hasn't expired and you do either a rack attached to the bumper or a rack receiver welded to the frame and bumper, if damage occurs to the bumper or frame you won't be able to go to the frame manufacturer for any help.
personally, my bikes are not cheap and i refuse to put them somewhere that i can't see them while traveling.
luckily, i have a truck so i have options. i currently use a step bumper-mounted fold down Swagman bike rack on my tow vehicle. that way i see them in the rear view mirror. it holds the bikes high enough to clear the tongue/batteries on all but the tightest of turns.
but even if i had a SUV, i'd go with a vehicle roof rack first, a tongue-mounted system second, a front-mounted receiver third and storing them in the trailer fourth.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC