Hi NicElua!
I think it might be a good idea to at least try it out. If it makes you feel more comfortable, you could start with an even smaller amount of time...like 5 minutes or so. It always seems like so much longer than it is, so 5 minutes may actually be much longer than you are used to waiting and may even be enough. I think the main thing to look for are the pauses...that's what really tipped us off. Also, if you can stand in a place where you can observe your LO's body language, that can be really helpful as well. For example, Noah would always have his eyes closed and be moving his head back and forth and sometimes squirming a bit; it's how he "settles in", so to speak.
He couldn't see us, so we would just pop in and glance at him every now and then and if he was doing that, we knew sleep was near.
I hope it goes well!! Keep us posted!