My observation over the years has been that Poncirus and it's hybrids (perhaps Citrus as well) grow in at least 2 very distinct types of flushes:
1. The initial Spring flush pushes many buds, favoring the higher ones to a degree. This multi-bud growth tends to be lateral, approaching horizontal. Because this growth spurt is shared among many branches they individually tend to be shorter. If the tree is mature enough, next Spring's flower buds develop on this growth. If these twigs receive too much stimulation, they can bloom in the same year, known as "June bloom" although in can occur in June or July.
The next major flush occurs in late July or August and consists of fewer growing points and much more upright vigorous growth. If the rapidly growing shoots can't support their own weight they may arch over and fail to remain upright. It's these upright shoots that provide the following Spring's buds for the next season's short lateral growth, repeating the whole process.
I have never seen direct flowering on the late season, vigorous upright growing shoots.
Short lateral growth off of previous year's upright flush, commonly seen during Spring flush. segentrange top grafted on Poncirus.
Vigorous midsummer upright growth on 5* citrumelo.
