only keysends are being used to send to pubkeys currently. To lightning addresses we use do utilize lud 12 comments but also include in the custom records field the message, inside field 34349334 (as well as the Satogram identifier field 6789998212). Currently we just ensure that the lightning address supports comments, but are not taking into consideration the allowable length. In practice it seems lightning address providers are not adhering to the length that their lightning addresses specify.