If you report the faults within first 30 days, and Skoda is unable to fix them (and dealer not booking in car for a while is not fixing), then should be able to reject without questions.
There is also the vehicle not as advertised, if a feature is not there, then the sale contract is not 100% fulfilled. The normal practice in these situations is to offer you a price reduction as you are effectively getting substandard item. You do not have to accept this offer, or could counter-offer with something like £1000 off or rejection still takes place. No one else can place a value on how you value a particular feature.
As a general rule, beyond the 30 days, dealer has to be given a chance to rectify the problem (one chance, can’t keep having a go at it), if they can’t fix it (and a partial fix is not meeting the rectification criteria), then can still reject, but would be expected to pay for usage for time you used it. (As example if you had it 3 months, paying the equivalent of 3 months contract hire PCH rate would be reasonable, being asked to take big loss to cover a potential resale margin isn’t, a realistic deduction is bit of a grey area), so won’t get 100% of your money back.
If you do reject, not obliged to get a replacement from same dealer (even if they offer you a deal), you are totally at liberty to take your returned cash and buy something from elsewhere, even another car brand.
Don’t worry about the dealer ending up with a rejected car, or moaning about inconvenience or losing money, not your problem, they have their own contract with Skoda where they can get remedies.