This MR adds corrections to the number of HT hits in TRT Ar straws when using overlay instead of full digitisation. Supporting slides with plots are available at https://cernbox.cern.ch/s/OkKBRXTjeaRiSCj.
This MR is needed to fix the modelling of TRT PID observables when using overlay (for example photon conversion reconstruction).
Tagging @beddall.