/shrug. I answered your question, which in one form or another has been asked dozens if not hundreds of times.
It matters not what communications topology you are using, RS-485, ControlNet, DeviceNet, EtherNet, Profibus, even SneakerNet. If the specification or manufacturer recommends specific cabling, hardware, connectors, USE IT. If there is not spec, then use the absolute best quality componants you can, and be smart. Do not crimp solid wire into an RJ-45 for example, plug it into a typical 'Office Store' type switch or hub, and expect it to work. Sure, it probably will. For a week, a month, maybe even a year, before you begin to get very strange, intermittant errors.
I've seen more installations be labeled as "S**tty jobs, s**tty company" simply because someone decided to save a couple bucks and use the shielded cable they had laying on the shelf, rather then the specified cable.
Not only for communications either. Not taking a hard look at encoder cables can also get you into trouble. Encoder type, driving capacity, cable capacitance, frequency, length, and load can all affect if an encoder is going to work or not, or again, if it is going to seem like it works mostly.
1000 perfect successes are always forgotten. It's the one, singular screwup that you are remembered for.
If someone deviates from specifications, especially if it is from pressure from a client or management, make sure that someone signs a piece of paper acknowledging that they understand that performance, operation, and or safety might be compromised by "XYZ" deviation from specification.
Later on, you at least have some evidence.