Damson St Julian rootstock in 3m square space

I covet a damson tree ( Farleigh specifically as I want to make jam) but am finding it impossible to get hold of a dwarfing rootstock damson. The next up is half standard bush on st Julian rootstock. The space is roughly 3m square, it could grow beyond that but would start to cast shade on my planting areas.
Is it possible to contain growth by pruning carefully? Or is it likely to turn into a bit of a monster? Any advice gratefully received.

Thanks Lardman, it’s useful to know that disease is a consideration when pruning. I have found that the dwarfing rootstocks are hard to come by, they are all gone already ( certainly from the reputable nurseries).