I don't know how limited strikes are possible with 22 deeply embedded targets .. and without a massive slaughter of civilians.
"Limited Strikes" is a common phrase that really means, "limited to specific targets to achieve the goal." You're thinking about this in terms of civilian casualties because (and I'm only surmising here), you're thinking like the Hamas. They launch weapons to
anything within range to express displeasure. Casualties are their goal, and since they have an unlimited budget, they don't worry about how effective they are. This does more to harm their cause than help, but they don't seem to realize that.
A modern military cannot afford such childishness. A modern military is extremely expensive so when they expend munitions (spend money) they MUST have a measurable effect. Therefore strikes on Iran, cannot be launched at just anything. They must hit the target, and only that target. Anything else is a waste of time, material, money, and lives. ANY civilian death is counter-productive to a modern military's goal. So limited strikes on Iran must be exactly on target or the mission is considered a failure.
Absolutely no other country in the world is as good as the US at this. No other country in the world spends the billions the US does at preventing civilian casualties. The best way to do this this hit your target and
only your target. Blasts wasted on anything but the target are wasted blasts.
Lastly, the latest deep penetrators the US has can blow through 200ft of hardened concrete. If that's not enough, well then 200 ft of material have been removed or rendered ineffective. The next one will surely have the desired effect. Iran's very expensive buried facilities have no chance. Honest negotiations are Iran's only real opportunity.
Oh, and only a few of Iran's nuclear facilities are deeply embedded. Everyone talks about them, but the deeply embedded ones are the minority. Most are very easily removed targets with common munitions.