I would like to get this feature added to the addon.

Was trying to ignore mob casts that would target friendly NPC's so that i would only display those targetting my party without having to create multiple triggers for each party member.
Having a Smart Group or Party option in caster's target dropdown menu would allow me to do that but the option doesn't exist.

Thanks in advance

Found a solution. Blizzard made NPC's mob that give no count and RP casts a different NPC ID.

I still think this would be a nice thing to have anyhow

so, to be clear - the ask is that if i have e.g. caster's target - unit - raid, then that test would pass if UnitIsUnit(state.destUnit, "raidX") evaluates as true, for any of the raidX unit tokens?

Yes. Smartgroup being the most obvious usecase