Hi Minty,
In answer to your question, I discussed this with a guy on my open day and we came to the following conclusion .... can't see how they would enforce the £4,500 if you never started training with them as it was explained the bond was to cover "initial sims and line training". If you never got to that stage then I don't see how they could enforce it. It would take a clever lawyer to argue that case.
i.e. If another airline hires people in the interim and Jet2 lose out on someone they wanted then they have only themselves to blame for penny pinching for a few months and not offering a 100% contract up front.
It would appear that TCX has recognised that come April finding a qualified pool of pilots eager to sign up for 7 months will be harder now that the sandpit and companies like Jet2 are scooping up people just now in their droves. The pool is being overfished.
I genuinely hope this is the first nail in the coffin of P2F, line training bonds, 70% contracts etc.