i don’t advise waiting to buy a TT on that rationale.
if one of the TT firmware hackers can figure out how to get hub support into the AVR32 usb host stack, it would satisfy the use case you mention, and be enormously useful for other devices using libavr32. (it’s not an easy task and has foiled a number of smart people. the gauntlet is thrown!)
btw, adding another physical USB port isn’t the answer and won’t “just work.” (alas)
an i2c expander module that just forwards grid I/O might be a DIYable solution.