Tweak a Note

plutus-ledger-api/src/PlutusLedgerApi/V1/Value.hs

@@ -387,7 +387,8 @@ We check equality of values of two key-value pairs right after ensuring that the
 disadvantageous if the values are big and there's a key that is present in one of the lists but not
 in the other, since in that case computing equality of values was expensive and pointless. However
 
-1. we don't really know whether this can be a common situation
+1. we've checked and on the chain 'Value's very rarely have more than 3 constructors, so we optimize
+   for the most common use case
 2. computing equality of values before ensuring equality of all the keys certainly does help when we
    check equality of 'TokenName'-value pairs, since the value of a 'TokenName' is an 'Integer' and
    @(==) :: Integer -> Integer -> Bool@ is generally much faster than repeatedly searching for keys