Grafted apple trees

Does anyone have experience with 4 varieties of apple grafted on one root stock? How well do they work?
I have a very small area for growing a fruit tree but I am interested in trying a small one.

We inherited a long-established 3-variety apple tree with our property and it provides us with loads of apples each year for cooking, freezing and eating

If I recall from Brian Minters presentation in February, when asked a similar question, he said to stay away from these types of trees. I cannot remember his reasons though. As Ely points out, some do prove productive. When space is limited, we do have to be flexible. Good luck!

The reason Brian said to avoid grafted trees, is that some of the grafts are stronger growing trees than the others grafts and the stronger graft will take over, thus making the weaker ones die out. Happened to my neighbour. I would find an apple tree you like, don’t worry about a pollinator as there will be one in the neighbourhood somewhere. I have a single tree Jonagold and it produces tons without another pollinator in my yard.

Thank you for the wise advice everyone. Perhaps I will try a single tree and see what happens.