180° hybrid phase balance

Hi!

I am currently designing a double-balanced microwave mixer (9...10GHz) and was wondering about 180° hybrids. What phase balance would you consider acceptable i.e. not significantly deteriorating mixer performance. I couldn't find any rules of thumb. My initial design is 177...183° in the desired range (I designed it in Microwave Office, of course I'll check it with 3D simulation and after fabrication it is expected to be even worse, so this is the best case scenario), and I was wondering whether this was good, or I should consider using multiple sections instead of the textbook schematic.
My question is really just this: is plus-minus 3...5° phase difference good enough?
Thanks in advance for any answer!

P.S. to get ahead of some questions and concerns: it is for a MSc thesis so
1.) it would be profitable to go for a more complicated one, I know
2.) it doesn't need to be REALLY good, just working
3.) I also have to make a local oscillator, tunable bandpass filter (both MCU-controlled) then some USRP programming with RoF measurements as another aspect of the field, so I would not like to waste a lot of time with multi-sectional hybrids if plus-minus 5° is a good phase balance, hence my question

There are many double-balanced mixer types. Some of them are affected more or less by the balance accuracy.
Generally a +/-10% variation of the balance increase by less than 1dB the insertion loss of the mixer. Or for active mixers, reducing the gain.
The port-to-port isolation of the mixer may be affected also, more or less, by the balance accuracy.
Only a simulation can give you the right answer.