"Sculpt Spells" modification

From the D&D5e PHB, p.117, the School of Evocation:

SCULPT SPELLS
Beginning at 2nd level, you can create pockets of relative safety within the effects of your evocation spells. When you cast an evocation spell that affects other creatures that you can see, you can choose a number of them equal to 1 + the spell's level. The chosen creatures automatically succeed on their saving throws against the spell, and they take no damage if they would normally take half damage on a successful save.

This is a pretty cool ability, and I like it, but I think it's just a little too potent. If a warrior has to think twice about the cost/benefit ratio of shooting arrows into combat, I feel that a wizard should likewise have to weigh up whether or not they really should be dropping a Flame Strike right on their own location.

To that end, I intend to modify it thus:

1. The "pockets of relative safety" become truly only relatively safe. The Evoker can shape their spell to flow around creatures, but the effect is this:
• The creature being avoided gets to add the wizard's spellcasting ability modifier to their saving throw. (If the wizard includes themselves in the spell area-of-effect and already gets to add their spellcasting ability modifier, they don't get to add it again.)
• If they save, they take no damage. If they fail, they still take half damage. If they fumble their save, they take full damage.
2. Creatures in intimate physical contact — e.g., if grappling, or being swarmed by hundreds of flesh-eating beetles — count as a single creature for the purposes of shaping the spell around them. The wizard can choose to affect both of them or neither.

I think this should have the effect that I want, which is basically to keep the ability's usefulness, but remove the guarantees, so that the wizard actually has to consider whether to cast a spell that might damage their allies.