Hi y'all,

I've just published a draft of a BIP to add Elliptic Curve operation op codes
as a soft fork utilizing the existing Taproot infrastructure and current tap
leaf version.

My primary motivation is enabling the commutation of the top level Taproot
output public key within Bitcoin Script. Alongside introspection enabling op
codes, this enables the creation of a new flavor of on-chain state machine
within Bitcoin Script. The set of op codes is also generic enough to enable
several other use cases related to (optimized DLCs, partial musig2 signature
verification, EC based sigma protocols, etc).

A total of 4 op codes are proposed (each allocated from the existing
OP_SUCCESS) range:
  * `OP_EC_POINT_ADD`
  * `OP_EC_POINT_MUL`
  * `OP_EC_POINT_NEGATE`
  * `OP_EC_POINT_X_COORD`

The full BIP text can be found here:
 * https://github.com/bitcoin/bips/pull/1945

A reference implementation in `btcd` can be found here:
  * https://github.com/btcsuite/btcd/pull/2413

--Laolu