Does this mean you block all of Wikipedia? And what will you do once encrypted SNI becomes popular?
Ignoring ESNI will probably work fine for a good length of time. If pornhub implements it or something I'd probably have to revisit. Or, since I control the clients I might disable it in their browsers.
If enough people bark up the filter vendor's tree I'm sure they'll add a checkbox to drop esni traffic. They added one for QUIC recently.