For backtesting you need not care about subtle differences. But when live trading you should know how long it takes to download the contract chain from your broker. If longer than one bar period, you can obviously not load it at any bar and must load it less frequently. Preferably once per day and outside market hours. If you have problems, we have a service for programming your options strategy.

The ivolatility option formats are very different and change all the time, so you must normally adapt the code to the format of your data. We also have a service for that.