I assume that if you join it with "end device" rather than "router" settings (not sure if that's documented here on the ST forum threads on the same topic), it should do that. I haven't tried it, so I can't say for sure, but you should still be able to use it with XCTU to map your network.
I definitely don't mind having them as repeaters, however. They're pretty cheap (the Grove dev board I used during its setup wasn't, but I'm hoping this $6 USB board works for regular use after that) and even the PCB antennas non the non-Pro models seem to work quite well, plus they're one of few routing devices that play well with Xiaomi. All wins in my book (and aside from possibly Xiaomi--I'm not convinced they change routes easily if at all--even if you add the XBee as a router, most ZigBee devices should find another path back to the hub if they are otherwise in range of it or another repeater, so having it offline shouldn't cause problems).