Thank you for the excellent suggestions. I suppose the iFrame method would work the most efficiently and not make the TW too heavy.
I have another idea. If I could create an SVG that’s larger than the “window” or frame it appears in, if could function like a map, although it wouldn’t have any zoom functions. SVG maps are pretty heavy, but PNGs and WEBPs are light.
Yet another solution would be just to host our own map tiles on a server. I’ll look into it.
By the way, I’m calling out for a discussion on TiddlyWiki’s Geospatial Plugin and OpenStreetMap as I intend to make a presentation to help drum up some interest within the two communities. I’m hoping to get a meeting online so I can further familiarize myself and have a working model that’s presentable, compelling and useful. I’m open to any ideas.