I just purchase a d4i too lol. But it's a old d4i, not a novo. I read up there isn't a off mode, meaning to say e dive mode cnnot be off even when swim in a deeper pool?
I think your question is about gauge mode (aka off mode)
On d4i novo free dive mode is called off mode.
On d4i off mode is called free dive mode.
There is gauge mode for suunto d4i. meaning you don't want to use the dive computer calculated dive times and etc. Some people want to use their own tables and this will turn on gauge mode. The dive computer will then only measure time and depth without consideration of any previous dives, no-deco dive time, safety stop, no fly time..
Please correct me if I'm wrong, it's called the free dive mode. It will only measure depth time. And once you change to free mode aka scuba bottom time, the no fly time is 48hrs and you can't switch to nitrox or air mode until the no fly time finish countdown. Also you must remember to switch back to nitrox or air after it finishes countdown 48hrs before your next diving or it will countdown again in free dive mode.
I'm looking at the manual and it shows this on page 84
Just a question though, why do you want to exceed the Conservative dive computer calculation? Are you going to try deco dive or tech dive or something? I think they will use another type of dive computer with deco type of table calculation.