The problem I see with this is that's completely separated from my main overall site design. Sure, it gets the job done, but it creates two sources of truth, and I wouldn't be able to do, for example, a single layout that included a 3D view of the driveway (where this fence will be) alongside the elevation showing the footing detail. @Rookie65's suggestion gives me that flexibility.
Thanks to both of you for taking the time to respond to my question, really appreciate the helpful folks here for newbies like me.