Ah, thank you for clarifying, as I really have only seen it referenced in passing! I don't recall anyone here on VJ who qualified for that.
Most here would recommend a spousal visa over the K-1 - even those of us who did a K-1 back in the day, when it was cheaper and faster.
The big advantage to the CR-1 is not having to adjust status. And, as we saw during the pandemic, a spouse is a legally recognized relationship, which is prioritized by US immigration.
If it were me, I'd proceed with the wedding as planned and have the USC file the petition asap. I've also seen MANY Canadians recommend giving birth in Canada, for various reasons. I'll tag @Ontarkie to give perspective.