Eugenia/Syzygium is exceptionally forgiving of very hard pruning and back-buds prolifically, which explains why they are so popular as topiary. You can prune to whatever shape you like with no need to be concerned the plant won't fill back in. If you take it back hard enough you will, of course, have a bare spot temporarily during the short period while back-budding and regrowth occurs.
Here is one in a pot that went from this:
To this:
Back to this:
all within the span of 3 months ..... and that's in a pot!
Al
