Maybe Cloudflare could have a browser plugin that preemptively creates "tokens", or essentially just mines Cloudcoins that you then spend to bypass CAPTCHAs. That way you could make it much more expensive than 5 seconds of CPU and there'd be zero delay (or perhaps not even the Cloudflare splash page). The use case for needing to constantly bypass CAPTCHAs is rare enough it seems reasonable to ask those people to use a browser plugin.