I have noticed on one of my slight big young common alder (3years, 6feet tall) the new growth right at the tip broke and side branches started developing fast, but one of the side branch that was close to the tip started growing more upwards. Well that would not be so special as the branches tend to have a bit of r upward curve in general.

I have to say I grow them for reaching great heights, currently in air-pot then put them in the garden, mainly as a rather opened screen, some light to pass, but to grow fast and straight up while being a deciduous tree.

My question is, since the new growth the tree is soft I can train the top branch to go up straight on a tall stake, but would that take the role of the new vertical growth or such thing is not even possible with alders or betulaceae?

Right now I feel like this should not work, what do you think?