In my opinion the importance of a special visit for snagging is unecessary.
The finishes are to a good standard to begin with, KMare have their own inspectors to ensure before the property is handed over by the builder to them, that the fundamental finishes are met. You will be given a snagging sheet by KMare (amongst other things such as keys etc) at the Notary office when you complete. You then have a month to complete this and return it to them. You make your own observations when you are actually in the property which is best because the water and electricity are on etc. KMare must contracturally carry them all out.
We paid for a professional to do our snagging in May because we coud't get out there. The amount of things he picked up were minimal and we could have found them for ourselves when we completed. This cost us £400.
We completed 2 July and found that the things highlighted had not been carried out so we added a further 10 things. We did find that we had to wait longer than I had expected or hoped (particularly as we felt one or two things were priority) but at the end of the day, the works have been carried out.