Sharing a cache with other users introduces its own set of problems, e.g., cache poisoning. The problems that arise from shared DNS caches gave rise to "solutions" that in turn introduced further problems.

For transparent proxying, i.e., hotel internet, I use a local forwarder and a remote recursor listening on a non-standard port and it has worked flawlessly.

I prefer to serve static address info via authoritative DNS or /etc/hosts. I have other methods of getting DNS data besides querying caches. I have no need for DNS caches. Most websites I visit do not change addresses frequently. I also like to know when they change, if they ever do.

I have not experienced any problems with DNSCurve.