Of course they are doing so. If they weren't it would be military mal-practice.
I've spent a few minutes watching live video from Gaza with audio. When I hear the jets that usually means bunkerbusters are coming up shortly.
The detonation of a bunkerbuster has a particular visual signature. Sort of like you see from an explosion inside a tunnel. And the sound is more thump than boom.
I’m in Nahariya, which is 12 klicks from the Lebanese border as the crow flies, much longer if you’re driving down twisty mountain roads. Nearby town and site of ancient Roman-built aqueduct tunnel just to the North of us by a few klicks and on top of a mountain is Rosh Hanikrah, which was evacuated and a missile battery put in place. I regularly hear the launches from there, which sound like a bang. But today I was hearing those thumping noises, which if it’s bunkerbusters would be coming from tunnels on the Lebanon side of the border, unless they found the openings on the Israeli side. Don’t see anything visual, because we’re down in a valley, and they’re firing from high ground, and Lebanon is way over thataway, after Tzefat and then the Golan.