i top mine always. even new plants before they flower
just to keep them short.
yes, they produce several stalks, and you have to thin the fruit/flowers.
if i have 3 branches, i thin 2/3 of the flower buds off weekly, or every other week.
this brings it back to normal fruiting numbers, and the fact that the leaf area will be higher
means you can really support more fruit, except they might be smaller,
so, i keep it at removal of %66 of the flower buds (for 3 branches)
obviously the numbers will change with a different # of stalks.
i have also had a problem in high rains, with a loaded tree full of fruit falling over
and if i have 3 branches, i will top each one at different times
i take abut 3 inches off the top every few weeks in summer.
leaving the other 2 untouched... then rotate to the others a few weeks later.
this way, you always have new leaf growth and new flower buds
but the tree is kept to size.
this is grown from a cutting of a mature tree
3 stalks. (top actually froze last winter)
2 main branches