You could probably even go lower than that... I'm sure a 1 ohm or .8 would still work. Don't go too high with those batteries though.
If it works the regulator is kicking in and limiting the amp output. 1 Ω at 3.3V draws 3.3A amps and that battery will not handle it. 0.8 Ω is 4.13 amps. So, no gain in vape quality but if the regulator fails and lets the atty draw full power from the battery, if you're lucky it will simply burn out. At worst the battery will vent. AFAIK, these batteries are ICR not IMR and when they vent they can be quite dangerous.
Not worth the risk to me