Update 1.21-notes.md

Author: TheRealWormbo

doc/1.21-notes.md

@@ -85,14 +85,17 @@
 * [x] Set up `package-info.java` with `@FieldsAreNonnullByDefault`, `@MethodsReturnNonnullByDefault`, and `@ParametersAreNonnullByDefault` (as Minecraft, Fabric API, and NeoForge do) to cut down the number of required `@NonNull` annotations everywhere
 * [ ] Change `Bound.UNBOUND_POS` and `ManaBurst.NO_SOURCE` to be proper `Optional`s instead of having a `(0, MIN_INT, 0)` position.
 * [x] Leverage wind charge/burst tech for fall damage protection (e.g. skies rod jump from avatar, cirrus/nimbus amulet, ~~maybe even Feather Feet effect in general~~)
-* [ ] Don't assume that all kinds of capabilities are attached to block entities
+* [ ] Don't assume that most kinds of capabilities are attached to block entities (`ManaCollector` and `ManaPool` capabilities will likely stick with that assumption for performance reasons)
   * [ ] Does `ManaReceiver` (and its child interfaces) really need to know its own level and position?
   * [ ] Check if Mana Splitter really needs a block entity
   * [ ] Figure out if red string block binding can be implemented without a block entity (e.g. catch block updates in facing direction and store bound distance as block state property)
   * [ ] Corporea Funnel and Interceptor technically shouldn't need a block entity (Funnels currently use it to remember their position in case of replayed requests)
   * [ ] Similar to `WandHUD` there should probably be a corresponding capability for the Manaseer Monocle HUD rendering.
   * [x] `WandBindable` should be a capability and be used to bind Force Relay targets.
   * [x] `Wandable` should not be restricted to block entities and should be used for forming the Mana Enchanter and non-binding interactions with Force Relays.
+* [ ] Check if `ManaNetworkHandler` is really still needed
+  * [ ] Try implementing closest collector/pool search the way the Copper Golem finds chests. (it's the only reason we maintain a collection of mana pools)
+  * [ ] Figure out a different way to construct the burst trajectory visualization on the client. (that's the other reason we maintain a collection of mana collectors, even though mana collectors aren't inherently tied to firing bursts in the first place)
 
 ### Feature candidates (potentially breaking changes)
 (Completing this list is not mandatory for a release.)