Adding 1-2 more DPS moves per healer except Sage (Sorry, they have more attacks than the rest of us) also wouldn't break the bank.

Imagine them adding a 2nd DoT to SCH, and making it so Deployment Tactics had 2 charges and could also spread DoTs if targeted on an enemy like old Bane (and how Deployment Tactics currently works in PvP). That's barely anything, but really adds more engagement in dungeons and in raids since your deployment isn't just for 1 mechanic now, it's for 2.

Imagine giving WHM an extra spell that combos with Glare III called Blinding Light. Yes, it's only 1 extra spell, but you're also hitting a different button instead of the same one all the time.

Imagine giving AST an AoE damage field like the old Shadow Flare that they can set down in addition to playing with their cards. Practically nothing, but more engagement.

Healers need barely anything DPS wise to make them more fun, and it wouldn't cause any real issues.