Your big ISPs BT, TalkTalk, Sky, PlusNet will usually swallow the costs, but smaller ISPs will pass them on. The fees seem accurate to me.
Certainly there would be a cease fee if one wished to migrate from uno TTB MPF to another ISP supplying a BTw service (plus additional fees if one left uno TTB MPF within 12 months.)
However if one wished to stay with uno and upgrade to TTB fibre (if available) together with the line rental probably going to BT based service also with uno, i.e. SMPF, maybe then there would not be a cease fee - perhaps Matt at uno can answer that if he sees this thread?