It's just so sad that this is not possible now.
Fam flights are possible, but just not usually on an ad-hoc basis. ATCOs and ATCAs come under one the DfT groups allowed FD access during flight 'for the purposes of enhancing flight safety'. It just depends on the particualr company whether and how they are arranged.
easyJet allow fam flights for ATC, you just need someone in the know to send the right e-mails. PM me if you want.