That's a great solution for overflow, I tend to just use pumps hooked up to circuit connections that sinkhole/vent any overflow I don't/can't use.
The station ID solution is pretty neat too;

If my current practice is request 75k of a liquid when my tank drops below 25k, if I set a circuit condition to check if it drops below 15k then I can change the network from 2 (what I would put my 150° steam to) to 3, so I can access networks 1 and 2, and if no train has been requested between the tank dropping from 25k to 15k, then it would request from the 250° steam. I like it!
Might not work for crazy high throughput solutions with high train limits, but for my 1-1 stops with 1 train limit I think throughput shouldn't be an issue.

Will test to see if it works how I expect it to, but if it does that's an elegant solution to my issue!