Icons licenses?

[cdauth]

I am the developer of FacilMap. FacilMap has a big overlap with Osmand in some of its use cases (namely trip planning and keeping notes about places), but its focus is on online collaboration and it doesn't have any offline capabilities like Osmand.

One way how people would potentially use FacilMap and Osmand together would be to plan a trip on the computer using FacilMap and eventually import the data into Osmand for offline navigation. FacilMap provides a way to export maps as GPX, and as part of FacilMap/facilmap#246, I'm trying to make the GPX exported by FacilMap more compatible with Osmand.

One challenge is to map the marker icons from FacilMap to <osmand:icon> tags in the GPX. FacilMap has a selection of icons containing the Open SVG Map Icons and some Bootstrap 3, Font Awesome and Material Design Iconic Font icons. Osmand has a selection of icons that seems to be stored here, and they seem to be taken from Open SVG Map Icons (CC-0), OSM Icons (CC-0 and CC-by-SA 2.0), icons8 (proprietary license) and Flat Icons (Creative Commons BY 3.0)? I could find information about this in this, this, this and this file. Some files also seem to mention a GPL license or other CC licenses.

Considering that Osmand's icon selection is similar to FacilMap's but much bigger, I'm thinking that it might be nice to simply copy Osmand's icons selection into FacilMap. That would also make mapping the icon names in the GPX file trivial. But I'm a bit confused about the licensing and which icons it's allowed to include in FacilMap, which uses AGPL-3. My best guess would be that the icons in the icons8 folder are under a proprietary license and all the other are CC-0 or some other CC license. But even there I'm unsure which ones need attribution and where I can find the attribution?

Could someone give me more insight which of the icons can actually be selected as marker icons in Osmand and what the licenses are?