Here's a (flowering) update on this one. Right side branch has been cut back and is in process of being regrown with better structure. Quince is in a deep pot with mossed top and shading to promote a better root spread.
It will eventually go into this blue pot that really compliments the flowers when it has a complete silhouette and better surface rooting
Some close ups on the flowers
Tree is now back budding after defoliation & cut back (see stem closest to camera going from the right to centre).