HTTP_mirror_pool.md

@@ -133,6 +133,12 @@ Actions:
  - Incrementally remove from the pool mirrors that prove too slow
    in practice.
 
+### Longer term
+
+This probably won't happen in 2021 but it would be good on the longer term:
+
+ - tails#17731
+
 # Initial research
 
 See [archive](HTTP_mirror_pool/archive).