Can healing be considered negative damage for the purpose of the Wild Magic sorcerer's Spell Bombardment?

Question

Wild Magic sorcerers get the Spell Bombardment feature at 18th level (PHB, p. 103):

When you roll damage for a spell and roll the highest number possible on any of the dice, choose one of those dice, roll it again and add that roll to the damage. You can use the feature only once per turn.

By multiclassing, feats, magic items or wish, it is possible for a Wild Magic Sorcerer to cast healing spells such as cure wounds.

Can healing damage rolls be considered “negative damage rolls” for the purpose of Spell Bombardment (granting an additional healing die if one of the dice gets rolled at max value)?

Answer 1

No, healing is not "negative damage".

There is no 'negative damage' mechanic in 5e, so healing is healing and damage is damage.

Answer 2

No, healing is healing and damage is damage. They're two different things.

The only place Spell Bombardment might help, sort of, is the life transference spell from Xanathar's Guide to Everything, p. 160 (normally available to only clerics and wizards). It deals 4d8 necrotic damage to you, then heals somebody else for twice the damage you took - so in that case Spell Bombardment could increase the damage you take, and thus increase the healing you do (at cost of your own HP, obviously).