It's going to need at LEAST a couple weeks for steeping probably. I didn't see what sweetener you used, was it ethyl maltol or sucralose. If it's EM, that can mute some flavors. To me, 20 drops of sweetener seems like a LOT, but I am a "reluctant" sweetener. I use FA supersweet (which is sucralose) and in 90 ml bottles, I really at max use 4 or 5 drops of sweetener, and often you can get more "depth" in recipes by using marshmallow, merengue or cotton candy which are all fairly sweet in their own right.
Just... break it down into smaller bottles, let them all steep and try one after ONE WEEK and see if you notice changes. If you try using it now, you may be tempted to think that it isn't "strong" enough (although I will agree that when coming from storebought juices, sometimes more flavoring percentage is needed at first) but since you've started with one recipe I would really not add to it (at least not the whole thing) if you want to set aside one smaller bottle to steep and add a small amount of a flavor that doesn't require a huge steep time that might be complimentary to what you have (fruits and berries mostly) you could try that, but you still aren't really going to get a good sense of anything MUCH until some steeping has happened. Shake often, that will speed up steeping time slightly.
Best of luck,
Anna