I have two sets. One on a TW and one on a DR650. Love them. One set is 8 years old, has been used a lot and is still in great shape. I don't have a rack on the TW, though.
On the top pic you can see the straps going over the seat. They are adjustable with velcro for length.
On the bottom pic you can see the mounts as installed. It does not look as if a rack would interfere, but no guarantees.