Just to reassure I owned a house that was slap-bang over the Victoria Line, in fact it ran under our house and garden in Stockwell.
When we bought it our deeds had a section saying we only owned the top 10 meters of our land - under that it belonged to TfL.
Remembering that the Victoria Line was far less deep than Crossrail2... only 25 meters if I recall correctly as opposed to 80 meters for Crossrail2.
In five years we never felt or heard anything at all. In fact the only time it was evident was if you were sunbathing in the garden,face down, you could feel the tiniest of rumbles through your tummy!
Therefore I wouldn't worry at all!