I know ripper93 (who makes awesome Foundry modules) has recently made a free online tool for converting images to webp. It’s original intent is probably so people can use it for Foundry, because Foundry and webp are great together, but it might be a nice option to direct people to that for file conversion: https://webp.theripper93.com/
Someone I’d played with before was like. Hey, I’m planning on running a campaign in Delta Green, who’s interested? And I looked into it and thought. Well, seems cool! And the rest is history.