If it's going to different cities.. sure it's fine... but since the loadfactor script is changed, i suggest 0.5 airliners to use 1 frequencies instead because it affects 0.5 frequencies more than it does to 1 freq.
Without competition 0.5 frequencies to different cities make more money than 1 frequncies to different cities.
If you do a 0.5 frequency route without competition you can almost double the fare vs. 1 frequency on that same route. It may be slightly less than double so you don't make quite as much money on the route.
BUT....
Since you're only operating a 0.5 frequency you only use up half the hours on the route, while still making just as much money. If you do it for all your routes you've basically given yourself a 48 hour airplane. It's a cheap unrealistic way to double your plane's hours, and in my mind it should be classified as cheating.
No more than one 0.5 frequency route per plane is the rule in real life, and it should be the rule in the game.
The only exception is if you can trace a realistic daily route for that plane. For example, if a plane can do a 0.5 frequency route from City A to City B, another 0.5 frequency from City B to City C, and another 0.5 frequency from City C to City D. That would mean the plane spends one night in City A, the next night in City D, then back to City A and so on.
The unrealistic stuff is when a plane does 0.5 frequencies from one hub to 7 different cities during a day. That would mean the plane overnights in 7 different places at once, which is obviously unrealistic.