FAE would do nothing. Roast everything above ground, yes, but subterranean impact would be nil.
B61 Mod 11 would be perfect. Problem is, I doubt Israel has any, so they’d have to rely on mundane nuclear ground strikes.
FAE can with proper delivery change the psi enough to scatter some grey matter in or around.... but agree it wouldn’t be as effective on the hard centers.
Ever hear of a deep penetrator test with Mk84 JDAMS where one target was sparkled by a tacp or designated AC and then a flight of F16’s dropped milliseconds apart multiple JDAMS on same point of impact to drill a conventional hole in the deep hard target .
I think is was Satan’s Needle or some silly test name..... old age memory as to specifics eludes me yet .....it was one hell of a hole.