Rok: sorry for the delay. I've actually been fiddling with a solution. A couple of years ago, I was trying to crowd source people's travel routes using Survey123. I designed a form for them to fill out the information I wanted as a point. I then created a line feature class with minimal fields that would allow me to associate the two feature classes (though the point should have been at the beginning of the line). That worked at the time and, because Survey123 has better ability to provide detail/description of what you want (vs. a popup feature class table), I thought it worked OK.
I'm now trying the same thing again but instead created a gdb, uploaded to my AGOL web map. When you edit/draw any of the points, lines or polygons, you fill in what I hope is a fairly obvious set of fields. At the moment, it's a web map but I'll soon create an App that'll allow Information instructions in a popup. Here's the link to this web map, should you want to take a look: https://arcg.is/0zTGyS You can go ahead an create a symbol or two, just be sure to delete them and, just in case, do them out of the main area of interest... . Right now, guests have full editing controls, but I'll change that later using a View feature class for the app.
As a side note, this map is to crowdsource search efforts by a public volunteer group after the main search has been suspended. From that, I hope to determine priority areas to carry on future search areas (prioritizing areas that haven't been searched).
OK. Hope that helps!
George
