No, hook it back up, and check that it works. Vacuum advance tunes for the load element. It auto adjusts, advancing timing for light engine loads, no advance at heavy loads, idle, or when starting. You will give up crisp throttle response, light load power, and cruise fuel economy. If you have a weak motor, and drive at wide open throttle all the time, you can get by without it. However with that said, air cooled bugs had only vacuum advance, on many engines.
While a timing light is not necessary, it can help you verify settings, check advance curves and easily return to your setting, or trouble shoot problems. A tach is also handy, both are fairly inexpensive.