according to the FCA: 'Our guidance makes clear to firms that they should ensure that taking a payment holiday will not impact your credit score.'It really is ridiculous, but essentially you're asking your mortgage lender to give you a break because you can't afford it, the systems are automatic after that.
Hopefully someone will put something in place to protect against this
however you will still get charged interest on the mortgage during the freeze, and most likely your mortgage payment will increase slightly after the 3 months to make up for it. so it's probably not really worth it unless you REALLY need it.