I've seen raspberries throw runners 10 feet, I don't think they have a limit?

My raspberries are throwing a lot of runners this spring - even the Encore of which 1-2 died the first year, so I'm glad it's filling in the row (1 row over and 25 ft away from the TC). That and the Killarney (opposite end but same row as original TC) are sending some up, but most of them are very close to the original canes, even behaving nicely and staying in the row or on the edge.

The unknown fall-bearing variety I got off Freecycle is the most vigorous, it's sending a lot out in the other (south) direction, enough to start a new row so most likely it's them, but they all look the same at this age. If there were more coming up to the north of that row then I wouldn't have even questioned it, but there is just 1 between those and the TC, and a couple more to the other (north) side of the TC/Killarney row, and more at the Killarney end. Maybe those are less-well-behaved Killarney ;-)

Do TCB throw runners? Or do you have to tip-root them?

I think generally they do not but I have had some TC's pop up away from the crown without tip layering. If you disturb the roots (e.g. cultivate between the plants) you might increase your chances of having one or two pop up. TC will tip layer very easily, so if you are looking to propagate a few more, that would be the easier method for extra plants.