Render fixed element differently the first time it's rendered

[dylnclrk]

Wondering if anyone has ideas on how to achieve something kinda tricky with a fixed element. Somewhere in my document (several subpages in) I have a section. I want to render a subheader at the start of that section, as well as on the rest of the pages that the section spans.

The first time this subheader shows up, I want it to say "Subheader," but on all subsequent pages, I want it to say "Subheader (continued)." I'll post some pictures below to explain what I mean.

Is there a nice way to do this? I want to use a fixed element for the Subheader, and somehow make use of the render prop, but the issue is I don't really know which subpage the subheader starts on, as this section could be several pages in.

Images of what I want:

REPL demo setup