EGR on a 1.3 combo is usually pretty reliable. Early ones did have issues with sticking until a software update that implemented a self cleaning routine, but a 58 plate would of had that software from the factory.
No need to code anything when fitting a new valve on these, as it’s a pretty basic valve.
Given it’s still driving OK, makes me question what fault code is actually being stored. MAP or MAF faults on these trigger limp home mode, so I’d doubt there’s any issue there.
If it is an EGR fault code, is it an excess/insufficient gas flow, or an electrical fault?
Sounds to me like the garage are just seeing EGR and changing it without actually diagnosing the problem.