That's a good resource! Many of those are not 1-bit, which would require loads of work.
(Ab)using the font type to display icons gives us 96 icons per font if I remember it correctly.
Don't know if there is a size limit on the fonts, but it handles variable widths within the same font, which is great for icons like theese: https://kenney.nl/assets/bit-input-prompts-pixel-16
An alternative could be to load all icons into individual canvases and put them in a deck. That would enable more than 96 icons, but is not as easy to move between decks. I haven't created any modules yet, so there might be a good solution to this.
Another alternative, that might actually be the best one, is to simply store the icons as gif-files in an folder and drag them onto Decker when needed.