Stack Audio have recently announced their AUVA speaker isolators, which claim to absorb vibration. They don’t use compliant decoupling like sorbothane, but rather cells of tungsten particles which are said to absorb vibration. £700 or £1000 for a set of 8.
https://stackaudio.co.uk/auvaisolator/
https://stackaudio.co.uk/auvaisolator/