Hi Ted,
welcome to the forums!
You can use multiple Zaquencers side by side, but you don´t get more steps, just more tracks (4 per Zaquencer). I think it´s best to treat them as independent devices in your mind.
Also yes, you need a separate license per BCR.
If you need more steps, you can always use the “pattern chain” function in one Zaquencer. This will play patterns consecutively. Note that while in chain mode the patterns can not be edited/stored (they can, but a save would have to happen before the switch to the other pattern, which doesn´t really work in practice).
Cheers,
Christian