Display MoreCastSpellByName function do not have 2nd parameter in our API, unless function is hooked by the addon, which means it can be hooked by another addon and lose its 2nd parameter.
Greetings
It is using this function Oo
https://runesofmagic.gamepedia.com/API:CastSpellByName
there is a second parameter. Maybe it isn't changed in CoA?
Taken from our API page, I am not entirely sure if it is correct, but as I said, reason of issue might be an addon is hooking this function wrongly which is removing 2nd parameter, so it wouldn't be related with RaidHeal addon.
Greetings