It's been a long time since I've done anything with URail. Its implementation actually pre-dates FLUPs--URail came in NAM 20, while FLUPs didn't arrive until NAM 24.
The original URail setups done by GoaSkin were all Dual-Networking, with only URail-under-Road and the transition portal being available. The RUL0 entries for the FLUPs crossings, oddly enough, involve CheckTypes for LightRail plus another network (even if there is no LightRail-based crossing involved), whereas the URail ones are Rail plus another network. It may come down to a quirk with how the query tools resolve the particular transit types involved. If Chrisim were still around, he would be the guy to ask, was the main guy for both FLUPs and URail, and probably did the most experimentation (at least since the early days) with CheckTypes.
-Alex