It does look to me rather like a non-problem which, a cynic would say, was being addressed by a party in Govt who expect to benefit from putting hurdles in front of voters with less orderly lives.
This tactic has been used aggressively in Republican States in the US, where the impact has been greatest among often impoverished - and predominately black or Hispanic - inner city communities. Hopefully measures will be taken in the UK to prevent that happening. But I am suspicious in part because I really don't think there is much of a problem - polling cards are delivered by Royal Mail, a trusted organisation, to individuals at the addresses registered on the Electoral Roll. There isn't much opportunity for fraud unless, say, a son uses a father's poll card.